The worst ettiquette is not re-racking your weights.
I do get sick of people always wanting to pose in the mirrors at the gym. You have a mirror at home, use it and not the one at the gym. I swear there are a few guys that spend more time looking at themselves than lifting.
As far as the video I have to agree that the guy is a douche. I didn't think he was trying to be funny, was he?