Looks like he's having fun, but straight front leg is a sign that he's sitting in the back seat too much. If he needs more setback to float, tell him to dial in more setback, it's tough to ride properly with your front leg straight as an arrow!!!
Whats with the knees together when he is inn the toe turn after the 1:20 mark...?
I was wondering the same thing. Anyway, it looks like your friend + some lessons = good snowboarder. He seems to be doing alright, just needs some tips to point him in the right direction (?). He's way better than I was at that stage ^^