Yea, it's sad about Ribeiro. Motorcycles can be dangerous, and aren't to be messed around with. The bike is the boss. Me and my dad ride a 1600cc Roadstar, and choosing not to wear a helmet on a bike is a bad idea. I mean if you are going really fast, the helmet isn't going to help much but most crashes happen at slower speeds where a helmet could very well save your life. Learning to ride in bad weather, and watching out for asshole drivers can be really tricky as well.
I wish him the best though in his recovery.