I don't see how. No more than someone shooting their spouse while "cleaning" their gun proves that you shouldn't clean your firearms -- just to be on the safe side.
Bottom line: If you are carrying a gun -- HANDLE IT SAFELY!
I think that these incidents with cops are more frequent because they always carry and take it for granted that they have their gun with them. When "ordinary" citizens carry, we are certainly more careful.
Absolutely, I handle my 9mm as if it were a priceless relic. I am conscious, almost to the point of paranoia of where the barrel is pointed. Maybe because us 'ordinary' citizens would be held far more accountable for 'accidental misfires' in crowded theaters.