Kudos. I have always been squarely against forcing children to hug/kiss to be polite, as part of a game, etc.
I have not seen The Hunting and will have to look it up. I am concerned, though, with the underlying message in the scene that you describe that boys don't have to deal with sexual violence and have never had to think about it.
Sexual violence against boys exists and is not rare or uncommon. The difference is that it is not acceptable to talk about it. I have no doubt that some of the boys in that classroom would have already been sexually abused, assaulted, and harassed. But it is not okay for them to talk about it.
We have talked about it with our girls and are increasingly giving them permission to talk about it, but the same is not true for boys. Their abuse is ignored, denied, shamed, and minimized.
Be sure to give that precious boy of yours permission to talk about what makes him uncomfortable; about people who touch or treat him inappropriately, whether male or female, old or young; and about giving as well as getting consent. It is no more acceptable for a girl to assault a boy than vice versa.