It would depend on the relationship. If it is a good friend of my son's I MIGHT try to smooth things over with the parents - even if it means paying more. But honestly - offering to pay $30 is plenty enough to cover 1/2 of a new jacket or to fix the zipper.
Kids get frustrated when playing physical games - it happens. If it happened frequently with the same child (which it does not sound like since OP's son felt so bad and offered his own money) - that's the only time I would even speak to the parents.
If it was my kid - I might want an apology (depending how angry the pusher got) but that's it - would NOT expect any money. If her child isn't allowed to hurt expensive clothing - He should sit and read a book at recess.
Kids get frustrated when playing physical games - it happens. If it happened frequently with the same child (which it does not sound like since OP's son felt so bad and offered his own money) - that's the only time I would even speak to the parents.
If it was my kid - I might want an apology (depending how angry the pusher got) but that's it - would NOT expect any money. If her child isn't allowed to hurt expensive clothing - He should sit and read a book at recess.