Cat Fight!

I have two young male cats. They are great buddies! Long story short...
I accidentally shut my bedroom door on the very tip of Willies tail. He freaked out and was screaming and I immediately opened the door panicking. My other cat Bernie happened to be right next to him when this happened. They both freaked and got into a spat chasing each other for about ten seconds. As soon as they separated we just left them be for a minute in their own hiding spots to calm down. Of course they were breathing heavy and all puffed up. We didn't want to make them freak out more and attack us, as they do have all claws. Willie ended up with a scratch on his nose from Bernie. Lots of fur everywhere. No injured tail.
Now they are not happy with each other and are having stare downs and growling at each other. I feel horrible cause this was my fault. We seperated them for a while. Now they won't go near each other. Anything I should or shouldn't do to help them get over this and get back to being best buds again? Or is this no big deal and they will get over it.

i suggest reintroducing them http://www.thecatsite.com/a/introducing-cats-to-cats

I think you can watch them for a bit; separate them if they get aggressive again.  You can try treats, talking soothingly to both, brushing them with the same brush (to mix their scents together again) and just providing a calm atmosphere in general.  Basically try to help them associate positive with each other again.  If the do start to fight again; separate them completely and re-introduce them with the steps in the article linked above.  Hopefully you won't need to go with that route; but if you do I would give them a few days completely separated to calm down.

Good luck!  Keep us updated on how things are going please!

So, basically, Willie thinks Bernie bit his tail...  And poor Bernie's feelings are hurt because he is innocent.  

It may take a while for Willie to let go of his grudge and for Bernie to stop sulking.  Give them time.