This top-heavy monster is Ben Tameifuna of Waikato, doing a very convincing impression of Paolo di Canio versus Arsenal in 1998. Unlike Paul Alcock, di Canio's target that day, referee Glen Jackson's tumble to the ground showed no hint of theatrics whatsoever.
It seems as though Jackson accepted that he was in a bad position, having come through the posts from the Waikato in-goal area as North Harbour pressed for a seven-pointer to take a late lead. For his part, Tameifuna immediately looks to the position of the ball after moving Jackson out of the way, which suggests that no malice was intended.
Tameifuna was sent to the bin in the aftermath of the push, but it was for a different infringement entirely - we can clearly hear Jackson say that the yellow card was for "playing the ball on the ground" and not "throwing me like a ragdoll on the ground".
It was a pretty unceremonious barge by the big man, but it's certainly not unusual to see rugby referees be knocked this way and that in the course of their duties at the breakdown.
One suspects that Jackson was glad to see that his accidental assailant was the one to have committed the binnable offence at the next phase.