Not sure whether that was a factor. A fairly intense storm blew through the area around 10:30 or 11:00PM. I don't know whether that was before/after or whether the storm affected that specific spot (it was a localized storm). It went over my house before it got there and dropped a brief period of torrential rain which at times included dime-sized hail.

That night I was out on the water about 8 miles from that spot. I came in before the storm. Prior to the storm the wind was under 5 knots and the conditions were hot and humid. It was a full moon, so the ambient light would have been good except when the storm clouds were in the area.

My conjecture:

27 people on a boat like this is a lapse of judgment (understatement). Given that it was hot and humid (unless it had an air-conditioned cabin) my guess is most of the guests would have been outside on the fore-deck and stern, and if any were on the foredeck that would have added weight high to increase roll-tendency (perhaps too many on the bridgedeck, too). If they crowded into the cockpit, it would have been squatting low aft (but people tend to try to find a comfortable spot to sit so my assumption is they would not all have been in the cockpit).

A sizable wake might have caused it to roll excessively and go over, or dip the stern quarter which would have filled the cockpit quickly and it would have gone under from that point, stern down. If the kids in the cabin were wearing PFDs the flotation would have prevented them from swimming down and out.