In the

    United States Court of Appeals
                  For the Seventh Circuit
                      ____________________
No. 17-3602
JEFFERY A. KOPPLIN,
                                                  Plaintiff-Appellant,
                                  v.

WISCONSIN CENTRAL LIMITED,
d/b/a CN,
                                                  Defendant-Appellee.
                      ____________________

              Appeal from the United States District Court
                 for the Eastern District of Wisconsin.
                No. 16-cv-588 — Pamela Pepper, Judge.
                      ____________________

  ARGUED SEPTEMBER 18, 2018 — DECIDED FEBRUARY 1, 2019
                ____________________

   Before SYKES, BARRETT, and ST. EVE, Circuit Judges.
   SYKES, Circuit Judge. Jeffery Kopplin brought two claims
against the Wisconsin Central railroad under the Federal
Employers’ Liability Act (“FELA”), 45 U.S.C. §§ 51 et seq.
Both rest on the same allegation: that Kopplin injured his
elbow in an effort to operate a broken railroad switch while
employed by Wisconsin Central. The district court entered
summary judgment for the railroad in part because Kopplin
2                                                 No. 17-3602

could not prove that the broken switch caused his injury.
While the parties raise several other questions, that alone is
sufficient to affirm.
                       I. Background
    Prior to his injury, Kopplin worked for Wisconsin
Central as a train conductor. On January 24, 2014, he pulled
a train into the Fond du Lac yard. To bring the train onto the
correct track, Kopplin had to get out and “throw” a switch,
which involves pulling a handle to correctly align the tracks.
The weather that morning was severe, with below-freezing
temperatures and 20- to 30-mile-per-hour winds. As a result
ice and snow had built up inside the switch’s mechanisms.
Kopplin tried to remove the ice and snow with a simple
broom—the only tool Wisconsin Central had provided—but
after straining himself for several minutes, the switch would
not budge.
    Kopplin claims that this effort was the initial cause of a
long-term elbow disability, though the evidence is less than
clear. A video of the incident shows no immediate signs of
injury. And Kopplin never mentioned any pain symptoms to
his coworkers until two hours later—time in which he
continued to perform other physical tasks.
    After his physician diagnosed him with medial and lat-
eral epicondylitis, Kopplin took time off work to receive
treatment. Among other things, he received an effective
pain-relief injection in February. By April the injury had
fully healed. But in August the pain suddenly reemerged
when Kopplin tried to drive a riding lawnmower one-
handed while holding his son. After that his career as a
conductor was effectively over.
No. 17-3602                                                   3

    Kopplin then brought two related FELA claims against
Wisconsin Central, both alleging that the railroad was
responsible for the broken switch and the injury it allegedly
caused. The first is a run-of-the-mill negligence claim. The
second is a negligence per se claim premised on Wisconsin
Central’s alleged failure to comply with 49 C.F.R. § 213.135,
the regulation that sets national standards for switches.
Kopplin’s sole causation expert was Dr. Etienne Mejia, who
testified by deposition that the pain-relief injection Kopplin
received often provides only temporary relief, which could
explain the pain’s reemergence. However, Dr. Mejia conced-
ed that he never investigated whether something other than
the January 24 incident could have caused the initial injury.
In fact, he testified that he knew so little about Kopplin’s job
that it would be mere speculation to say throwing a switch
even could cause the elbow injury. Moreover, he admitted
that he did not investigate whether Kopplin’s other physical
activities—say, riding a lawnmower in a dangerous fash-
ion—could have caused the renewed elbow problems in
August.
    For two months after the deposition, Kopplin made no
attempt to supplement Dr. Mejia’s testimony. But after
Wisconsin Central moved for summary judgment, Kopplin
attached to his response a new affidavit by Dr. Mejia. The
contents of that affidavit were markedly different than the
deposition testimony. Dr. Mejia definitively stated that the
January 24 incident caused the elbow injury, explaining that
the nature of the injury was so clear that there was no need
to even consider other potential causes. In the end, Kopplin’s
effort to bolster his causation evidence was in vain. The
judge refused to consider the affidavit because it contradict-
ed sworn deposition testimony. And without the affidavit,
4                                                    No. 17-3602

she found Dr. Mejia’s testimony unreliable under Daubert v.
Merrell Dow Pharmaceuticals, Inc., 

(1993). As a
result, Kopplin had no causation evidence at all.
    The judge addressed several other questions, including
the extent to which regulations promulgated under the
Federal Railroad Safety Act define the standard of care for
FELA actions and the extent to which 49 C.F.R. § 213.5(a)
imposes a notice requirement for negligence per se claims.
Because the failure to prove causation is fatal to both FELA
claims, see Walden v. Ill. Cent. Gulf R.R., 

, 364 (7th
Cir. 1992), we need not reach those issues here.
                         II. Discussion
    We review a summary judgment de novo, asking wheth-
er the movant has shown “that there is no genuine dispute
as to any material fact.” Hansen v. Fincantieri Marine Grp.,
LLC, 

, 836 (7th Cir. 2014) (quotation marks
omitted). We review the exclusion of the affidavit “for abuse
of discretion, giving the trial judge much deference.” Buckner
v. Sam's Club, Inc., 

, 292 (7th Cir. 1996). Finally,
“we review de novo a district court’s application of the
Daubert framework. If the district court properly adhered to
the Daubert framework, then we review its decision to
exclude (or not to exclude) expert testimony for abuse of
discretion.” C.W. ex rel. Wood v. Textron, Inc., 

,
835 (7th Cir. 2015) (citations omitted).
    We start with the admissibility of Dr. Mejia’s affidavit.
As the judge explained, a party may not “create an issue of
fact by submitting an affidavit whose conclusions contradict
prior deposition or other sworn testimony.” 

. The affidavit here contradicts Dr. Mejia’s testimony in
No. 17-3602                                                       5

at least two ways. First, Dr. Mejia was asked at his deposi-
tion whether “there could be other various causes of this
type of condition” besides the January 24 incident. He
answered unequivocally, “Yes.” But then in his affidavit,
Dr. Mejia wrote that there was no need to consider other
causes because “[t]he etiology and diagnosis [were] clear”
that “the patient suffered from left traumatic medial epicon-
dylitis as a result of the injury of January 24, 2014.” That
clearly contradicts his original statement that other causes
could be at play.
    Second, Dr. Mejia was asked at his deposition whether
throwing a switch “seem[ed] like the kind of activity that
could lead to the tendinosis,” and he answered, “It would be
speculation on my part … .” That admission is squarely at
odds with his affidavit’s definitive conclusion that Kopplin
injured his elbow throwing the switch. See 

(exclud-
ing a supplemental affidavit’s detailed description of a fact
when the affiant had disclaimed knowledge of that same fact
at her deposition).
     To be sure, we have carved out several exceptions to the
general rule barring contradictory supplemental affidavits.
None apply here. For instance, we’ve said that a party may
offer an affidavit in response to a summary-judgment mo-
tion “to clarify ambiguous or confusing testimony.” Bank of
Ill. v. Allied Signal Safety Restraint Sys., 

, 1171 (7th
Cir. 1996). Yet nothing about Dr. Mejia’s deposition testimo-
ny was ambiguous or confusing: without qualification, he
said that other factors could have caused this condition.
Similarly, while we have held that an affidavit may contra-
dict sworn deposition testimony if “it is based on newly
discovered evidence,” 

even Kopplin concedes
6                                                 No. 17-3602

that Dr. Mejia received all of the materials supporting his
affidavit before his deposition. Finally, a new affidavit may
be appropriate if the earlier testimony was “the result of a
memory lapse.” Cook v. O’Neill, 

, 298 (7th Cir.
2015). Kopplin argues that this exception applies because
Dr. Mejia did not have the full medical record at his finger-
tips during the deposition itself. But nothing in Dr. Mejia’s
responses indicates that he was struggling to recall what
those records said. To the contrary, his responses were direct
and honest admissions that he never considered certain
issues at all.
    Even if the affidavit were perfectly consistent with
Dr. Mejia’s prior statements, a larger problem remains. In
essence the affidavit sets forth a brand new expert opinion
on a topic beyond the scope of anything in Dr. Mejia’s prior
disclosures. In his original expert report, Dr. Mejia discussed
Kopplin’s treatment history and prognosis but never ex-
plained how the switch actually caused the disability. The
issue surfaced for the first time—at least to any meaningful
degree—in the affidavit itself. By then, the time had long
passed to disclose a new report on a previously unexplored
topic: Kopplin attached it as an exhibit to his summary-
judgment response on June 27, 2017, months after the district
court’s December 30, 2016 deadline for Kopplin’s expert
reports. See FED. R. CIV. P. 26(a)(2)(D) (“A party must make
[expert] disclosures at the time and in the sequence that the
court orders.”).
    Without the affidavit the Daubert analysis is relatively
straightforward. Under Daubert the court considers “wheth-
er the expert is proposing to testify to (1) scientific
knowledge that (2) will assist the trier of fact to understand
No. 17-3602                                                   7

or determine a fact in 

. The ultimate
question is whether the expert’s approach is scientifically
valid, which requires a careful examination of its “eviden-
tiary relevance and reliability.” 

The focus is on
the expert’s methodology, not his ultimate conclusions. See

    Both relevance and reliability are problems here. As to
reliability, the judge identified a number of causation ques-
tions that Dr. Mejia conceded he never considered. Each
concession significantly undermined the validity of his
methods. The most troubling were his admissions that he
never considered whether factors other than the switch
could have caused the initial injury in January, nor whether
other factors could have caused the renewed symptoms in
August. The judge found this unacceptable, and that was not
an abuse of discretion. See Brown v. Burlington N. Santa Fe Ry.
Co., 

, 773–74 (7th Cir. 2014) (faulting an expert’s
differential etiology not just for failing to “rule in” the
alleged cause but also for failing to “rule out” other potential
causes).
    As to relevance, only one of the opinions Dr. Mejia gave
at his deposition is even probative of causation: his testimo-
ny that the pain may have resurfaced in August because the
pain-relief injection Kopplin received often wears off. That
is, Dr. Mejia had one theory for how the January injury
could have had long-term effects. Even that is a partial
theory because he admitted that he did not know whether
throwing the switch could have caused the January injury in
the first place. He testified that it would be “speculation” to
say one way or another. Because Dr. Mejia’s opinion is only
8                                                   No. 17-3602

marginally relevant, there is little reason to think that his
testimony would be helpful to the trier of fact.
    Kopplin has two final objections. First, he argues that
even without the affidavit and despite all the problems with
Dr. Mejia’s deposition testimony, he should prevail because
the injury’s origin is obvious. It is true that we do not require
expert testimony when causation is so clear that “a layper-
son can understand what caused the injury.” Myers v. Ill.
Cent. R.R. Co., 

, 643 (7th Cir. 2010). For example,
a pedestrian hit by a truck would generally not need an
expert to prove the cause of his broken leg. See 

case is much different. There are several steps between
Kopplin’s effort to fix the switch and his long-term disabil-
ity, and none is clear. For instance, take the fact that the
injury resurfaced when Kopplin attempted to hold his son
while riding a lawnmower. To put it mildly, we are skeptical
that the average layperson knows whether operating heavy
machinery one-handed can contribute to medial and lateral
epicondylitis. And because it would not be obvious to a
layperson, expert testimony was indeed necessary.
    Second, Kopplin insists that his claims should survive
because Wisconsin Central’s expert Dr. Jan Bax noted in a
report that “Mr. Kopplin sustained a work-related strain to
his left-elbow on January 14.” But that one stray line does
very little work. To start, the report never says that the
broken switch caused the injury. It says only that the injury
was “work-related,” which could refer to a number of
different things. The report also oddly says the injury began
on January 14, ten days before Kopplin operated the broken
switch. Moreover, Dr. Bax faces many of the same problems
as Dr. Mejia—namely, that there is no evidence he consid-
No. 17-3602                                                9

ered whether other factors may have caused the injury. In
fact, there is no evidence at all that Dr. Bax’s testimony
would have been admissible under Daubert. Perhaps the
greatest flaw is that he never said a word about the
reemergence of the injury in August. One way or another,
Kopplin still needs admissible expert testimony that the
January 24 incident caused a long-term disability. That
report is not it.
    As mentioned, causation is a necessary element of every
FELA claim. See 

. So Kopplin’s failure
to present reliable expert testimony on that issue is fatal.
                                                  AFFIRMED.