What would you have done?

[Chloe]

When I collected my charge from preschool,the supervisor told one Mum in front of all the other Mums that she did not know what she could do with her son?As this Mum looked in the window she saw her child sitting on a chair away from the other children.I could see she was upset,she asked a member of staff what he had done and she replied he's been alright to-day.The Mum came out of school crying her eyes out(shes a single Mum) I comforted her as best as I could and arranged to meet her after lunch.In the meantime another Mum phoned her to say she had heard what the supervisor had said and that she was taking her child out of the preschool as she had been told the day before that there had been a case of bullying and when she asked she was told to look in the incident book,the supervisor did not want to know,this Mumhad been bullied when she was a child.
I feel that I should report this supervisor but do not want to cause trouble?Any thoughts?