it isn't all that hard to imagine the hull deck joint developing some leaks after a nice put down on its side. This joint is one of the weak points on many production boats, a little squeezing and it could crack like a walnut. Sheet metal screws holding it together aren't uncommon. I don't know how a Union 36 was put together, but I have certainly seen this in other boats. The last production boat I had was built with 1/4" bolts on 4" centers through the toe rail holding the deck on. That would be considered pretty good construction by most - and yet that is considerably weaker than anything else in the hull: a 1/4" bolt will shear at around 1000 lbs, 4" of even 1/8" laminate is good for at least 7 or 8 times that. If the hull is going to break in that area, that's where its going to happen.

Nevetheless, reading the transcript, it doesn't sound like it was a big contributor to the abandonment - just one of many factors.