This isn't a matter of him going around talking about it to parents, which would be stating his opinion. I'm sure he does that too, and I don't like it, but understand that's within his rights as an American to exercise his freedom of speech. He reported it to my work place, which has direct effect on my livelihood. He didn't just say he thinks I'm a racist, he said I was acting racist towards his daughter. If you make those types of allegations that can affect a person’s ability to provide for their family the burden of proof should be on the accuser to at least show there is some truth to that statement. He was called in to the school and giving the opportunity to provide examples of racist behavior and was unable to come up with anything at all, but would not retract his claim despite having absolutely nothing behind it. It certainly seems like slander by all of the definitions I've found online.
The ironic thing about this whole situation is I'm a very liberal person and I live in a community where Caucasians are a minority. I'm very aware of the horrible amount of racism that goes on in the world as I see it around me on a daily basis. This is the case of a loony parent trying to use a major social problem as a battering ram to get his kid more playing time and he doesn't care if it ruins someone else’s career in process. I stand by my assertion that it's a very sad world we live in if people can make these types of allegation without having to back them up.