all i see in this video is a douche who seems to be getting a massive power-boner from his racer poles.
heres the thing. even if the guy really did go out of his way to fuck with your friend (which didn't seem like the case in the video) your pal should have had:
a) the respect to not cuss the man out in front of his little kid over what was effectively nothing
b) the foresight to see that this gaggle of gapers might turn into a moving roadblock
and by far most importantly c) the fucking common sense to TURN THE FUCK OUT OF THEIR WAY. If the boarder was able to "spot the skier early on" as you said, the skier in turn should have spotted the border way in advance and had plenty of time to adjust his path a little to the right and avoid this entire situation.
honestly it didn't look like the boarder was starting static, like everyone else has said, its the skier going out of his way to start shit.
sidenote: props to the geezer on the board for not battering that racer. if someone cut off my nooby kid, hit me when i had the right of way, and then gave me lip for calling them out on their shit, the gloves would definitely be coming off. bottom line is your friend's a twat.