Either he couldn't swim a lick, or suffered some medical condition. If it was the former, he's an idiot. I give him a pass on the life jacket though if I couldn't swim at all, I would wear one when I paddle board. The 2nd thing is he wasn't attached to the board at all.. That is something I never do. I will not wear a lifevest but have it on the board per regulations, but that cord is always strapped to my ankle. If it was medical, he may have died no matter where he was, but anything else... Darwinism.