There were obviously problems since the man is dead. No, I don't know what kind of boat it was and I don't care. I guess it wasn't founded enough to survive the conditions since it sank. What is to discuss? How it happened? That's forensics.
So far as I know he could have sought refuge in Mattituck but didn't. Or he could have turned away from the wind and sailed back to Orient Point. But he didn't so far as we know.
What I do know is that in LI Sound sailing into a strong Westerly wind, can subject one to steep waves which can turn a sailboat around in direction. To elaborate, the waves can slow the boat to the extend that you can lose steerage and the boat can spin around from the waves. This can be extremely dangerous to crew who can easily end up in the water as the boat spins. I've experienced this on a 35' boat. It can happen on a 26' boat. You can quibble about the skill of the crew but a single handed guy in those conditions was in great peril, in my opinion.