Seeing how the towbar is still connected to the nosegear, I would guess that the towbar came adrift from the tug. It looks like the tug driver momentarily thinks about 'reconnecting' with the aircraft, only to think better of it and scarper off to the left side.
Perhaps the bar wasn't connected properly to the tug, or perhaps the bar failed at the tug end.
Fun to watch though - especially as no animals were hurt during the making of that short movie...