Is parliament really a place of non aggression? We see politicians standing up and shouting over each other daily.. The Westminster system is designed itself to be adversial and combative. Physical violence is obviously not allowed, however, aggression is part of the point of parliament. Haka is not physically violent either. I will concede if it is out of turn and prevents other members from being heard that it is disorderly.
I agree with you on TPMs stances on colonisation, but that is a seperate debate. Parliament has never been a place of non aggression.