What a terrible way to go.
Car windows can be broken, but you must use serious force or some kind of tool.
Had that been me, I'd have shot (then kicked) the window out. And I carry tire irons and a 4-way and other tools. Though I'm pretty sure the mechanical door handle would have worked (wet or not).
If nothing else, one of those there to help might have tried to crash his car into hers in the pond to get a door or window open. Heroic measures.
Speaking of Teslas, I played tag with one yesterday on my Valk (in and out of traffic) (safely on both our parts, but fun). Those are some fast cars for sure. But they can't change lanes with a motorcycle. So he lost.