The fact that they are good buddies again means that everything is OK. I've had situations in my house where the kitties even take turns at being the aggressor.

Think of it this way, Luna is Lily's teacher. They don't know that they are housecats so Luna thinks that she has to prepare Lily for confrontations with other kitties. If they were outdoor kitties then Lily would need these skills.

Also, I think we humans tend to take these things much more personally than cats do.

So its ok,