@ragingloli about twenty five years ago, I was coming home from a late night visit at a friend’s house and saw a couple of cop cars and an ambulance on a bridge on the road I lived on. I stopped and watched as they brought up a body bag on a gurney. When I asked someone what was going on, one of the onlookers said that a guy had rolled his pickup truck off the bridge, it had landed upside down in the creek, and he had drowned in the creek. The creek was never deeper than three inches. Seems he bumped his head during the crash, passed out and ended up breathing a lungful of water while hanging upside down in the seatbelt.
So while your scenario is pretty unlikely, drowning is a little bit of water is not always foul play.