Ok.

Without direction and intent, the spell simply becomes words coming from a person's mouth. This is a direct parallel to the n-word and the way it functions in society today. The n-word is just a word until someone picks it up and throws it with the intent to harm someone else.

So the Harry Potter demo of our fanbase likes to talk about context, right? But what you described is NOT the context. Felix didn't "throw his spell" at an african-american. He didn't even throw it at a person that could hear or see him for that matter. So the context is that neither of their usage was done in a racist manner. And it is a racist word, so without racist "intent" the racist "spell" loses all its power. And since there was no recipient there to even receive it, it couldn't possibly have done any "harm" even if it did have any power.

So Ethan is literally a hypocrite. Neither of them intended their language in a harmful or racist manner but there is one big difference - Ethan is a) an American with full grasp of just how taboo the word is in American society b) stupidly claimed moral high-ground c) throw a friend under the bus while giving another friend, JonTron, an actual racist, a pass.