It might be grounds for a civil lawsuit, depending on the specific circumstances, but no, any injuries incurred would probably not affect whether the State had evidence sufficient to prosecute the case. The one exception to that would be if the officer actually ended up getting terminated or maybe even criminally charged himself over the injuries. In that case, as a policy matter, the DA will often end up deciding to just drop the case if the only other option would be to heavily rely on the testimony of that officer (that wouldn't always be how it worked out even then, since sometimes they can make the case using other witnesses).
It might be grounds for a civil lawsuit, depending on the specific circumstances, but no, any injuries incurred would probably not affect whether the State had evidence sufficient to prosecute the case. The one exception to that would be if the officer actually ended up getting terminated or maybe even criminally charged himself over the injuries. In that case, as a policy matter, the DA will often end up deciding to just drop the case if the only other option would be to heavily rely on the testimony of that officer (that wouldn't always be how it worked out even then, since sometimes they can make the case using other witnesses).
