It would depend if it was a once off or a regular thing. If it was the former I'd be annoyed but accept it's something small kids do sometimes. If it's happened several times before I'd be wanting it addressed.
I kind of feel sorry for CC tbh. I was talking to someone who is a CC worker a while ago about this topic and she said it was a bit of a mine field for them bc on one hand they have a duty of care to protect the victims. But on the other, many children who bite do so bc they are placed into care too young for *them* and CC is basically left to deal with it as parents say they have to work and asking the child to leave/cutting hours is then the CC's fault.