you gotta go with the flow dude. when i started riding in the streets here (crowded southern cali town...no room on sidewalks) i noticed that most cyclists use the "point to where im turning" method instead of the "legal" hand signals.
i grew up on the hand signals, and remember with clarity how they were taught in my driver's license study guide back in missouri when i was a kid. so, logically, i immediately thought it was wrong of people to use the pointing method.
here's the thing: it's not an issue of legality or correctness; it's an issue of "what can i do so that people behind me will understand what i am about to do?". the hand signals are (from what i have observed) obsolete, and people just point to where they are turning. let the no-helmet dude learn from his own mistake when he ends up in a hospital's intensive care unit instead of paying a 35 dollar replacement fee to Bell for cracking a helmet in two.