He wasn't really adjusting the cam gear, but what happened was he was showin the engine to their friends as he pointed towards that area and without even knowing it he kept gettign closer and closer and then it happened.....

Usually it chews off your necklace or shirt if you are working on the car while is running. The moral of the story is either

#1 cover the damn cam gears and don't leave them exposed.

#2 dont' work on the car while is running.