Marion Barber has been hurt for the majority of the year, so I can understand him being a bit excited to get his 1st TD.
The funniest part of the video is that it wasn’t spontaneous.
Barber settles himself before going for the backflip only to fail miserably. The lesson here is don’t attempt a backflip unless you are 100% sure that you can complete it.
He is lucky he didn’t break his neck, just give the ball to the ref next time or do the Dougie.