Of course he could, then of course it would depend on your credibility in front of the jury. you have to understand that a civil tort action does not require proof beyond a reasonable doubt, only a preponderance of the evidence. With a cop that bad I would bet there are complaints on the record against him and even if you don't win you will put the blackmark on his record that will cost him a promotion and will make him lose the next time it happens. Even if you don't win you should press it on the principle of it. People in power must always be aware of the consequences and that they aren't above the law.
The other thing to remember is that if you don't give permission and he searchs anyway and finds something incriminating then the evidence will more than likely be inadmissible unless he has more than himself to say you gave permission or has something written.
