'Would you honstly go to the school and say, 'Well, the other kid started it'?
Because if you did it would make you sound about 7. ' No,not if you say 'I understand I might not have the fullpicture, but from what X says I believe thisnincident was caused by'- i do it allll the time and even when its wrong (usually,ds1 has no social understanding) it is useful in trying to unpick events.
I would never tell them to hit someone unless they were at risk;I have taught them the difference between that and self defence though (something you do when you beleive your safety is at risk and someone is actually attacking you at the time)- if so,meone was endangering my boys I'd be proud if they fought back then.
There's a massive difference between bullying minor and full on physical assaults but when it is a full on physical assualt you defend yourself. DS1 came home with shoes imprinted on him from being attacked by a gang of twelve: to my mind fighting your way out of that (as he did) is fine. At that point, you can get a teacher (there are no teachers on our yard, only supervisors who seem to vanish).
I didn't return ds1 tos chool though until it was sorted- had to do it that way, I felt, for any response but ever since have had Head on alert for it.