It would be instructive to know what the weather conditions were like at the time they got into the canoe. For example what was the wind and wind gusts?
I Googled some pictures of the point where it appears they got in the canoe. It’s a pretty good-sized expanse of water even though it’s not in the bay itself. I would guess, based on the the account, that there was a good bit of wind, certainly nothing you’d get in a canoe for. And obviously not wearing life jackets was very foolish. Although I’m guessing that even with life jackets they were doomed once the canoe had capsized, with the wind, the current and the hypothermia.