Tom performs a perfect "Heel Clicker" even if it was involuntary, when the bike seized at the end of the Ascot back straight. Two strokes are finicky things that require a black art to get the most out of them. After having it pinned for a good number of seconds down the straight, when you shut'er off completely you aint got no slippery stuff when the motor is still turning very high Rs and it can nip up momentarily, just enough to put you on your ass. One solution to this is to have a big fat idle jet to provide hopefully enough lubrication.