Is this Appropriate?

The father of a 4-year-old boy who got into trouble at school for hitting little girls is facing some backlash after he decided to punish his son by humiliating him.

 Last week, for one hour, Rob Devine  stood with his 4-year-old son, Tristan, on the side of the road in their hometown, and had him hold a sign that read, “I hit little girls.” 

“I want him to know you can’t go out and do these things and expect them to go away unnoticed,” he told ABC local affiliate WXYZ. But Devine’s actions may not achieve his aim. Because Tristan’s mother, Brittany Tweed, who apparently is separated from his father, told WXYZ she thinks the punishment was overly harsh. She also said the boy will not be going back to his father’s house, adding that she’s asked child protective services to intervene. 

Hmm, who do you agree with in this case, guys? Tristan's mum or dad?