Could the salt in the water have fucked it up?
I don't think salt would do much unless it was submersed for quite a while, or the phone wasn't rinsed off with fresh water before letting it dry.
Salt water conducts electricity way better than non-salt water. So it seems that it might have a better chance at shorting something out. Assuming it's possible to blow something in there up by simply bridging all the contacts together simultaneously.