The mother gave permission. Obviously.
When I was growing up, the paddle was the rod of correction and the teacher was given in loco parente rights of discipline including swats.
The problem in schools today is that teachers fear the students instead of students fearing their teachers.
If your kid was deliberately misbehaving in school and the school called and requested permission to give your kid a swat, would you deny it. And if you denied it, how would you deal with your out of control child?
Time out?
I would deal with my own child in my own way. Nobody hits my kid and especially not with a big wooden paddle. That is child abuse.