I am a teacher and I would never say something like that in front of the students. I don't think you are overreacting. However, I might have to agree with AM up there; raising hell might make life harder for your son in school. But at the same time I think it NEEDS to be addressed! I just think you shouldn't expect anything to happen to the teacher - especially if she is in the union. At best she might get a write up. How much longer do you have of school? Because at least you know this teacher won't be his teacher for much longer.

As an aside - running the mile as a requirement in fifth grade is ridiculous. Making it a requirement at all is ridiculous - I HATED running and I would have never been able to do it! I just straight refused in 9th grade. and I was stick-thin at the time. I just hate running! Not everyone is a runner!!!