While i'm no racing expert, I saw the move to be, while a little on the aggressive and desperate side, perfectly fine. Sure, he probably could have and should have waited till a proper overtaking spot, instead of diving down the inside of a chicane, and it was fairly obvious that he did it out of desperation rather than "omg i'm a better racer so i'll use my supreme racing skill to pass", but it happened, nick went off, no collision, get over it :\