I'm with this guy. You voluntarily assume a certain amount of risk being in any sports arena/gym/park. if you've gotta bail to avoid impact let the board hit them. They knew the risks of standing in the way so you're not going to be liable for assault or anything crazy. Shit, worst case scenario they might get away with breaking your board... still worth the lulz of the video you'd catch. Better yet, do slam into them and act more injured than you likely are (dat padding). Your friends will happily chime in that fatso got in your way on purpose.