Boys and girls, are you kidding me??!
I could easily see this dude place top 5 in the Aussie nationals, if that means anything..
Regarding arms extended vs bent:
As Shannon Best once said, it's all about the bar in relation to the hips.
Effectively the arms have to work against the legs when you load and pop unhooked, which is one reason why I don't think it's a particularly "aesthetic" move from the start - compared to compound movements in many other sports.
So when you load up as hard as possible, the arms can't keep up and are gonna be fully extended before you pop - which is not ideal, because it brings you into a semi-poostance position. So most pros have the arms slightly bent when they leave the water, then fully extend when they are in the air, pull the bar back back to the body and pass the handle.
So maybe he could be a tad more aggressive and allow the arms to extend more, but is it a make or break? Don't think so..
E.g. look at Keahi, often praised for his style. He has the arms already extended as he rides in, which I don't think is a good technique whatsoever when maximum pop/aggression is the goal. But when you ride in with enough speed and power in the kite, you still can get decent pop, and combined with fast spinning perform nice tricks - what Keahi certainly does.
So overall it's not the best vid I have ever seen, but the dude would comfortable smoke 99% of the folks out there.
Arms bent vs extended: Look at this guy, not a kook I suppose

Edit: It only shows a railey, so I am not accountable for potential bandwidth waste..