FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

JAMES CLEM,                               No. 07-16764
               Plaintiff-Appellant,
               v.                           D.C. No.
                                          CV-05-02129-JKS
G. LOMELI,
                                             OPINION
              Defendant-Appellee.
                                      
       Appeal from the United States District Court
          for the Eastern District of California
       James K. Singleton, District Judge, Presiding

                 Argued and Submitted
         May 6, 2009—San Francisco, California

                    Filed June 2, 2009

    Before: Procter Hug, Jr., Michael Daly Hawkins and
            Richard C. Tallman, Circuit Judges.

               Opinion by Judge Hawkins;
               Concurrence by Judge Hug




                           6567
                        CLEM v. LOMELI                     6569




                         COUNSEL

Karen Kreuzkamp, Morrison & Foerster, LLP, San Francisco,
California, for the appellant.

Vickie P. Whitney (presented oral arguments) and Christo-
pher J. Becker (authored brief), Office of the State of Califor-
nia Attorney General, Sacramento, California, for the
appellee.
6570                    CLEM v. LOMELI
                         OPINION

HAWKINS, Circuit Judge:

   Plaintiff James Clem (“Clem”), an inmate in the custody of
the California Department of Corrections, appeals from an
adverse jury verdict in his 42 U.S.C. § 1983 civil rights dam-
ages action, arguing the district court gave erroneous jury
instructions and that the error was not harmless. In the under-
lying action, Clem alleges he was beaten by his cellmate and
that a prison officer is liable for the attack under the Eighth
Amendment for failing to abate a known risk. Concluding that
the jury instructions misstated the law and that the error was
prejudicial, we reverse and remand.

                   I.   BACKGROUND

A.     Factual Background

   Although this is an appeal from a jury verdict, because we
conclude the jury instructions were erroneous, “the prevailing
party is not entitled to have disputed factual questions
resolved in his favor because the jury’s verdict may have
resulted from a misapprehension of law rather than from fac-
tual determinations in favor of the prevailing party.” Gambini
v. Total Renal Care, Inc., 

, 1093 (9th Cir. 2007)
(quoting Swinton v. Potomac Corp., 

, 805-06
(9th Cir. 2001)). The record therefore establishes the follow-
ing:

  Clem is an inmate in the custody of the California Depart-
ment of Corrections at the Mule Creek State Prison in Ione,
California. Clem’s cellmate during the time relevant to this
case was Inmate Godman (“Godman”), who was and is serv-
ing a life sentence for murder.

  Clem returned to his cell for an afternoon head-count and
found Godman in the cell, drunk. Godman had apparently
                        CLEM v. LOMELI                     6571
consumed a large quantity of home-made wine. As soon as
Clem entered his cell, Godman told Clem “I’ll kill you” and
threatened to beat him. Clem testified that, feeling frightened,
he “yelled” for the head-count officer, Officer Gabriel Lomeli
(“Lomeli”), to move him from the cell because Godman was
drunk and threatening to kill him. Lomeli told him to “[d]eal
with it.” For his part, Lomeli testified that Clem merely
explained he was “tired” of being in his cell and needed to be
moved. In any event, it is uncontested that Lomeli continued
with his count, walking away from Clem’s cell without inter-
vening.

   Shortly after Lomeli walked away from the cell, Godman
began severely beating Clem, breaking his jaw and knocking
him unconscious. Minutes later, officers arrived in response
to a “loud crash” and found Clem convulsing on the floor of
his cell. Lomeli and another prison officer radioed for medical
assistance and restrained Godman. Due to the severity of his
injuries, Clem was taken to an outside community hospital,
where doctors wired his mouth shut. Clem remained in the
infirmary for approximately one month.

B.   Procedural Background

   Clem filed this § 1983 civil action, alleging that Lomeli
violated his Eighth Amendment right to be free from cruel
and unusual punishment when he failed to alleviate the sub-
stantial risk that Godman posed to Clem.

   Prior to trial, Clem, appearing pro se, asked the district
court to instruct the jury that Lomeli could be found liable if
the jury determined he “knew that [Clem] faced a substantial
risk of serious harm and disregarded that risk by failing to
take measures to abate it.” Lomeli submitted his own pro-
posed instructions, following the Ninth Circuit’s Model Civil
Jury Instruction 9.25 (2007), which omitted the “failure to
act” element, stating instead that liability requires “(1) the
plaintiff faced a substantial risk of serious harm; (2) the
6572                           CLEM v. LOMELI
defendant knew of that risk and disregarded it; and (3) the act
of the defendant caused harm to the plaintiff.” (Emphasis
added).1

   Over Clem’s objection, the district court adopted Lomeli’s
proposed instructions, declining to give the “failure to act”
instruction. The court additionally charged the jury that it
could find for Clem only if an “act of the defendant deprived
[Clem] of his particular rights,” and that “[i]n order to estab-
lish that the act of defendant Lomeli deprived [Clem] of his
particular rights . . . , [Clem] must prove by a preponderance
of the evidence that the act was so closely related to the depri-
vation of [Clem’s] rights as to be the moving force that
caused the ultimate injury.”

   Following a one-day trial, an eight-member jury found in
favor of Lomeli. Clem timely appealed, arguing the jury
instructions erroneously omitted a “failure to act” charge.

                II.    STANDARD OF REVIEW

   Because Clem “challenges the [district] court’s [civil jury]
instruction as an incorrect statement of the law,” we review
the instructions de novo. Dang v. Cross, 

, 804
(9th Cir. 2005) (citing Galdamez v. Potter, 

,
1021-22 (9th Cir. 2005)).

                        III.      DISCUSSION

   “ ‘[J]ury instructions must fairly and adequately cover the
issues presented, must correctly state the law, and must not be
misleading.’ ” 

(quoting White v. Ford
  1
    A Ninth Circuit Model Jury Instruction 11.10 (2001) formerly
instructed juries that prison officials could commit deliberate indifference
also “by failing to take reasonable measures to correct” a substantial risk
of serious harm. A 2007 revision to the model instructions eliminated the
failure-to-act language. See 9th Cir. Model Civ. Jury Instr. 9.25 (2007).
                         CLEM v. LOMELI                      6573
Motor Co., 

, 1012 (9th Cir. 2002)). Each party
is therefore “ ‘entitled to an instruction about his or her theory
of the case if it is supported by law and has foundation in the
evidence.’ ” 

(quoting Jones v. Williams, 

, 934 (9th Cir. 2002)). A district court therefore com-
mits error when it rejects proposed jury instructions that are
properly supported by the law and the evidence. 

ever, the error in the jury instruction is harmless, it does not
warrant reversal.” 

(citing Tritchler v. County of
Lake, 

, 1154 (9th Cir. 2004)).

A.   Instructional Error

   [1] “ ‘[P]rison officials have a duty [under the Eighth
Amendment prohibition of cruel and unusual punishments] to
protect prisoners from violence at the hands of other prison-
ers’ ” because “[b]eing violently assaulted in prison is simply
not ‘part of the penalty that criminal offenders pay for their
offenses against society.’ ” Farmer v. Brennan, 

,
833-34 (1994) (quoting Cortes-Quinones v. Jimenez-
Nettleship, 

, 558 (1st Cir. 1988) (alterations
omitted); Rhodes v. Chapman, 

, 347 (1981)). “It
is not, however, every injury suffered by one prisoner at the
hands of another that translates into constitutional liability for
prison officials responsible for the victim’s safety.” 

Instead, prison officials are liable under the Eighth Amend-
ment only if they demonstrate “deliberate indifference” to
“conditions posing a substantial risk of serious harm” to an
inmate. 

well settled that “[d]eliberate indifference
occurs when ‘[an] official acted or failed to act despite his
knowledge of a substantial risk of serious harm.’ ” Solis v.
County of Los Angeles, 

, 957 (9th Cir. 2008)
(emphasis added) (quoting 

). Thus,
violations of the Eighth Amendment may occur as a result of
either “a prison official’s act or omission.” 

(emphasis added).

   The instructions given misstated the law. The jury was told
in Instruction 4 that it could find for Clem only if an “act of
6574                        CLEM v. LOMELI
the defendant deprived [Clem] of his particular rights,” and
that “[i]n order to establish that the act of defendant Lomeli
deprived [Clem] of his particular rights . . . , [Clem] must
prove by a preponderance of the evidence that the act was so
closely related to the deprivation of [Clem’s] rights as to be
the moving force that caused the ultimate injury.” Following
this Circuit’s current model civil jury instructions, the court
gave Instruction 5:

      In order to prove the defendant deprived the plaintiff
      of [his] Eighth Amendment right[s], the plaintiff
      must prove the following additional elements by a
      preponderance of the evidence:

      1. the plaintiff faced a substantial risk of serious
      harm;

      2. the defendant knew of that risk and disregarded
      it; and

      3. the act of the defendant caused harm to the
      plaintiff.

(Emphasis added); see also 9th Cir. Model Civ. Jury Instr.
9.25 (2007).2

   [2] In order to find for Clem, the plain words of the instruc-
tions therefore required the jury to conclude that Lomeli took
action in such a way that directly caused Clem’s injuries. Far-
mer could not be more clear, however, that direct causation by
affirmative action is not necessary: “a prison official may be
held liable under the Eighth Amendment . . . if he knows that
inmates face a substantial risk of serious harm and disregards
that risk by failing to take reasonable measures to abate 

(emphasis added).
  2
   “The use of a model jury instruction does not preclude a finding of
error.” 

(internal quotations and alterations omitted)
(quoting United States v. Warren, 

, 328 (9th Cir. 1993)).
                         CLEM v. LOMELI                       6575
   [3] Lomeli argues the instructions were nevertheless proper
because “failing to abate” a substantial risk of serious harm is
semantically the same as “disregarding” a substantial risk of
serious harm. While that argument might have some traction,
it is ultimately beside the point: the jury charge unambigu-
ously instructed the jury that it had to find not only that
Lomeli “disregarded” a substantial risk of serious harm, but
also that Lomeli himself took action that directly “caused
harm to the plaintiff” (by, for example, affirmatively placing
Godman in the cell with knowledge that he would harm
Clem). By improperly adding this extra element to Clem’s
burden, the instructions simply did not permit the jury to find
for Clem based on his legitimate “failure to act” theory of lia-
bility, standing alone. The jury charge therefore did not cor-
rectly state the law and thus did not “allow the jury to
determine the issues presented intelligently.” Fikes v. Cleg-
horn, 

, 1013 (9th Cir. 1995).

   [4] Clem is also correct that a failure to act instruction had
foundation in the evidence. There was evidence showing that
Lomeli heard Clem’s call for help immediately prior to his
beating, and that the officer took no steps to abate any risk to
Clem. Clem was therefore entitled to a “failure to act” instruc-
tion, and the district court erred in rejecting it. See 

-05.

B.   Prejudice from the Error

   [5] “ ‘An error in instructing the jury in a civil case requires
reversal unless the error is more probably than not harm-
less.’ ” 

(quoting Caballero v. City of Concord, 

, 206 (9th Cir. 1992)). Because we “presume preju-
dice where civil trial error is concerned,” the “burden shifts
to the defendant to demonstrate that it is more probable than
not that the jury would have reached the same verdict had it
been properly instructed.” 

alterations
omitted) (quoting 

).
6576                     CLEM v. LOMELI
   Here, Lomeli cannot overcome the presumption against
him because he has failed to address prejudice in his answer-
ing brief, declining to advance any argument or identify any
evidence to support a harmless error finding. He has therefore
waived the argument. See United States v. Gamboa-Cardenas,

, 502 (9th Cir. 2007) (where appellees fail to
raise an argument in their answering brief, “they have waived
it” (citing United States v. Nunez, 

, 958-59 (9th
Cir. 2000)).

   [6] Even setting aside the waiver issue, “it is more probable
than not that” the error here was prejudicial. 

. At the outset, we have previously recognized that
when “the trial court erroneously add[s] an extra element to
[the plaintiff’s] burden of proof,” it is “unlikely that the error
would be harmless.” 

. Here, the
instructions added an extra element to Clem’s burden of
proof: that some act of Lomeli had to be the “moving force”
that directly “caused the ultimate injury.” It is therefore “un-
likely” the error was harmless. 

is also generally more likely than not if “noth-
ing about th[e jury’s] verdict indicates that the result would
have been the same without the error.” 

entire
verdict consisted of the response “No” to the question, “[B]y
failing to remove him from Cell 115, was Defendant Lomeli
deliberately indifferent to a serious risk of harm to the plain-
tiff[?]” The trial court never explained to the jury, however,
what the words “deliberately indifferent” meant, despite that
they were the pivotal words on the jury verdict form. Because
we cannot determine one way or another whether the jury
understood “deliberate indifference” to include the affirmative
act element, we cannot say the verdict would have been the
same without the error. If the jury had been properly
instructed, it “may well have concluded that” Lomeli was lia-
ble to Clem for failing to abate the risk of harm from God-
man. 

. Accordingly, we hold the error
was not harmless.
                        CLEM v. LOMELI                      6577
  REVERSED AND REMANDED.



HUG, Circuit Judge, concurring:

   I add this concurrence to emphasize that model instruction
9.25, set forth in the 2007 edition of the Ninth Circuit’s Civil
Model Jury Instructions, does not adequately state the law and
should not be used by the district courts. The commentary to
the instruction correctly notes that the Supreme Court clearly
states in Farmer v. Brennan, 

(1994), that the
key inquiry in an Eighth Amendment conditions of confine-
ment claim is whether the defendant acted with “deliberate
indifference.” Yet the model instruction itself (like the jury
instruction given in this case) never mentions or defines the
term “deliberate indifference.”

  The 2001 version of the Ninth Circuit’s Civil Model Jury
Instructions correctly focuses on the term “deliberate indiffer-
ence” and explains what constitutes “deliberate indifference.”
Model instruction 11.10 states:

    On the plaintiff’s Eighth Amendment conditions of
    confinement claim, the plaintiff has the burden of
    proving each of the following elements by a prepon-
    derance of the evidence:

         1. the defendant acted with deliberate
         indifference;

         2. the defendant acted under color of law;
         and

         3. the conduct of the defendant caused
         harm to the plaintiff.

    To establish deliberate indifference, the plaintiff
    must prove that the defendant knew that the plaintiff
6578                    CLEM v. LOMELI
    faced a substantial risk of serious harm and disre-
    garded that risk by failing to take reasonable mea-
    sures to correct it.

9th Cir. Model Civ. Jury Instr. 11.10 (2001). This older model
instruction makes clear that the appropriate inquiry focuses on
the “conduct” of the defendant, which includes the defen-
dant’s “failure to act.”

   Had that instruction, or one that similarly explains the key
term of “deliberate indifference,” been given in this case, then
the interrogatory posed to the jury—“[B]y failing to remove
him from Cell 115, was Defendant Lomeli deliberately indif-
ferent to a serious risk of harm to the plaintiff[?]”—and the
jury’s response thereto would have been meaningful.

  I can fully understand why the district judge in this case
was misled by following our new model jury instruction. The
purpose of this concurrence is to ensure that others do not rely
on this erroneous model instruction in the future.