I completely agree, every card in the super rugby seems to be followed by a yellow. If there is seriously dangerous play during a game then a citing officer can pick up by themselves. They don't need the referee to bombard them with every rough tackle or scrap.
The card for 7 is sort of understandable. The TJ might not have thought it was intentional but at the end of the day, his knee went into someone's head. The two fellas who started fighting should have got yellows for punching the face but that will come up after the white card. If officials didnt see the original scuffle then theres not much that be done at the time.