Why should my son be punished for not sharing?

[Publicenema]

An upsetting incident at school today. My 4 year old bit another child because they were trying to take a toy off him. He was quite rightly told off for biting but then the teacher lectured him about sharing and told him to give the other child the toy. He refused and...long story...was sent home. I'm very clear that the biting was wrong but as far as I'm concerned the other child was in the wrong and should have waited their turn for the toy. I have always taught my son not to snatch toys, to ask politely and wait his turn. He is now extremely upset and asking what he is supposed to do when another child grabs his toys. What do I tell him to do?

www.ipsea.org.uk/what-you-need-to-know/exclusion-from-school

More details on illegal exclusion

www.gov.uk/school-discipline-exclusions/exclusions

What you should expect if your child is excluded

I've taught my (4yo) dd to hold onto a toy if someone tries to snatch it off her, and say firmly 'I'm still playing with it, you can have it when I've finished' (and to tell a grown up if they wrestle it off her regardless). And that if someone asks nicely for a toy in a shared environment like school, she should finish what she's doing with it and then when she's ready pass it on to them, as it isn't actually her own toy. She is territorial about some of her own toys, and I let her decide with those - if someone's coming over to play I'll give her warning and ask if she wants to put any of her 'special things' away so they're not out for somebody to play with. It doesn't work perfectly but she's pretty good most of the time.
I try to always make her feel good about doing the right thing - 'what a shame X forgot to ask nicely - that was kind of you to give it to them when you'd finished with it/I'm glad you asked me/Mrs Y to help.'
I'm not saying we've got it cracked, and we have come at it from the other side (dd's problem was that she wasn't assertive enough and would just let someone take something off her and then cry). Hope that helps though?