Looks like fun to me, what's he doing wrong ? 
Nothing really. His objective was to have fun, and he did. It is taught when shooting a full auto weapon, the best way to maintain control and prevent barrel burnout is to shoot in short bursts.
He is able to maintain control quite well, and if he wants to risk barrel burnout, so what. It's easy to change, not to expensive, and he doesn't have to worry about hordes of commies charging over a hill at him.
Some people just like to sit in judgment and point out what they consider are others flaws and faults.
This guy wanted to have fun, he did, and I would like to try that too. Who wouldn't find that a blast?
