I'm not sure that a little girl of 5 is a horrible child or a bully - I think she is not old enough for labels such as these.
I think it sounds like she has either not been shown appropriate boundaries around her behaviour, or has insufficient understanding of what she has been told and shown to learn how to moderate her behaviour.
FWIW I think the teacher appears to have dealt with it appropriately in this case - she was punished with the loss of golden time.
I'm not sure that cuddly teachers are par for the course much beyond reception TBH - but I would have expected her to speak to your son and ensure he was calmed down after the incident.
Were you bullied as a child? Is this why all of this seems such a huge deal to you? My children have been hurt at school, various times some accidental some most certainly deliberate, and I don't ever remember being in tears over it. And I am usually as bit of a softie really
I just wonder if this is bringing back bad memories for you and you are transferring your feelings of helplessness and misery onto your son.
Most kids get over this kind of stuff very quickly given a chance - and not making too big a fuss helps a lot imho!
I would talk calmly to the teacher tomorrow - mention the other incidents and say that you think there might be a pattern of behaviour delevolping towards your DS by this girl, and that it is running close to the line of being bullying in your view. Ask her what the school policy on bullying is, and whether in her view this meets the definitions contained in the policy document. By doing this you are putting down the marker that you are watching the situaion closely, and will expect the schools policy on bullying to come into play should any more incidents occur.
If she really does give you unsatisfactory answers, or appears off hand and disinterested, then tell her you are disappointed in her response and will take it up with the Head Teacher - 4 year olds talk sense sometimes Northener