The boy was older than the girl. 
My reason for supporting the boycott has nothing to with being right wing, it has to do with right and wrong.
1) this had nothing to do with race, just because the woman declared the man racist does not mean he is, at no point did he say or do anything racist.
2) He laid his hands on the boy.
3)  He tried to speak to the woman and get her to take action against her son, she responded by swearing at him.
4) Her son hit a girl.

Now taking these into consideration and looking at SPUR's response we see gaps in their logic for banning him not her.
They claim to have banned him for foul language, abuse, violence, violence towards women, and he is guilty and got banned,
But she is guilty of foul language, and her son of abuse, violence and violence towards women. No action by SPUR.
Thus the message I get from SPUR is the above is acceptable if your black and the other person white.
As for the owners convince the CEO to do the right thing or pay simple.