In addition to the comments above about design of the boat and possible accidents.
1. There's no such thing as a freak wave.
2. I doubt that the design would "pop" the boat back up to proper position after a roll as quickly as the most modern most safe designs.
3. Falling off a high wave would easily smash the cabin top away and unless there was separate sealed area underneath (and I don't know what the design was) water ingress would be immediate and probably catastrophic.
4. Sails, even stormsails, should have been taken down before shredding. It's easy to say that of course and in a huge blow or roll the sails could be torn loose from the gaskets securing them in their furled positions.
5. If there was only one epirb on-board I would be upset.
6. When conditions are so bad that you're under bare poles you should be in a survival suit with your personal epirb attached. That still may not save you, but it's better than nothing.
7. I noticed the dinghy in the youtube click was secured to the foredeck. I hope that wasn't the arrangement in serious offshore sailing in bad weather - a recipe for getting your dingy splintered or the supports tying it down ripped out.