I’ve never paddle boarded. But I have water skied and knee boarded, at times going very fast depending on who was driving the boat.
Is falling off a paddle board that traumatic and violent that it would cause someone that knows how to swim, to become incapable of controlling themselves in the water?
Paddle boards aren’t small. Wonder what the woman was doing to ‘help’ him. All he would have had to do is grab onto her paddle board.
How dark it was is important. But yes you can fall from a board and often the board will go the other way. So it would be about ten feet from you. There is a very slight chance of the paddle or board hiting you in the head. Doesn’t normally happen as the board tends to be pushed away if you lose balance. Normally the paddle itslef is a weak flotation device. and its hard to hit yourself with it.
Lets say there is no foul play. Then I would think that there was something just below the surface that he hit. A rock or sunken boat or part of an old dock. If it were twilight he may not have seen it below the surface. Lots of water fatalities happen this way. People think that every little shoreline is like a public beach, cleared of all hazards. But hides all sorts of things just below its surface.
There is a man-made lake in Seattle where one can rent windsurfer boards. It is a small lake but some years ago a guy fell off his board, it hit him in the head and he drowned.
Probably paddle board could cause the same situation.