I watched a J22 roll 360 degrees in Dallas many years ago. It was blowing like hell and we shouldn't have been out there. I think once the sails hit the water it provided resistance to the wind/waves on the hull and rolled the boat. Unfortunately the deck plate was left out of the fwd flotation...
Damn sad to see the loss of life. I don't think PFDs should be madatory, but I haven't left the dock without one on in MANY years. Just like a seat belt in the car, my PFD has become automatic for me. PFD's save lives. I invested in a good, comfortable inflatable with a harness. I hope like hell...