Concur. I envision the three of them at the stern, dinking with the engine and the long shaft. With the bow light, the right wave comes along and stands the boat up on end, and the three go overboard.
What puzzles me is why they couldn't get back to the boat. 55 degree water is cold, but not incapacitating. I'm thinking, being GIs, they've got to be fit enough to be able to swim back to the boat.
I can't imagine a scenario where they would voluntarily abandon ship. That would be worse than jumping out of a perfectly good aircraft. No mention of alcohol :(