Fisho's get nailed in Dovi

I'm curious as to why they capsized. They said the bilge alarm went off, then they tipped over. I'll bet a good bottle of whisky someone forgot to put the bung in. Not a problem when planning out, but as soon as you stop for a fish, water comes in, free surface effect or whatever you call it, it sloshes from one side to the other, and BOOM, boat tips over and your all swimming.

I'm obviously only guessing on the bung, but a boat like that shouldn't get water in it. Alloy trailer boat isn't going to spring a leak, its not carvel planked. Unless the forehatch wasn't snugged down, or the anchor locker or capstain chain was letting water in. But you'd think if it was that rough a sea state, they would have decided to bail?