What that teacher did is unacceptable to me. It lacks common sense and responsability. Something that controversial and that cutting edge for a group of 7 year olds should have had parental buy in first. Who knows, perhaps all of the parents would have said "go for it". The story might be a good one to teach the kids about the bigger world. But to just spring it on...that's not cool.

Consider it from this perspective, what if a teacher told a story about a bunch of niggers talking to a bunch of cunts about how Bill was holding them back... Not exactly something any of us would want to try and explain to 7 year olds.