OK wrong sport and not totally related, but I remember playing soccer about 20 years ago when i moved here (didn't know about Dutch rugby when I came) and in one game our striker was getting a lot of cheap kicks to the ankles and shoves in the back from their centre back. Our striker was 5'8, stocky and bit of a nutcase, the centre back must have been 6'5 and looked like an angry lock in the O'Connell mode.
At some point our striker must have issued a final warning to this bald monster, because the last thing I remember of the game is after the final ankle cutter, he turned around, used this colossus' shoulders for leverage, pulled himself to get head to head and headbutted him twice before they both fell to the ground in a heap.
Needless to say, the ref called the game off at that point but strangely enough nobody else from either team saw fit to intervene!