What a load of tripe you just spewed forth, you sir need glasses.
The girl (4) was white, the boy (8) was black. I have watched this video many times due it its poor quality and can assure you that your talking absolute rubbish. The birthday girl (not involved in any way) was black and celebrating her 4th birthday. 
The white father approached the black woman in a polite manner and asked her to take action, the woman responded by swearing at the man. He again responded in a polite manner which resulted in her hurling more insults at him. At this point he swore at her a walked away, SHE continued hurling abuse at him so he turned round and exploded.
He made a grab at the boy and told him to go apologize to the girl, the mother ripped the boy back.
AT NO TIME did the girls father tell the girl to hit the boy. 
Please ensure you gets your facts straight before posting utter rubbish.
PS would you do nothing if a boy slapped your daughter in the face?