Hi. First time posting in this subreddit. Sorry for format, I'm on mobile.

Okay so... 
Bit of background, two of my friends fell out about a year before this happened. They were best friends and ended up hating each other. I still talked to both if them because I didn't want to pick sides. Let's call these people C and R.

C and R both went to a mutual friend's party.  C noticed that R was being rude while the group party was eating. R was on their phone showing another person at the party (J) a video. They both had headphones in. C wanted me to mention this to J so I did. J didn't like this and told R. R told J that I was 'untrustworthy'.

 I began to ignore it and bottled it up for a few months until I finally broke down. This meant a teacher got involved because they can't have a crying child in school. The teacher pulled R out of class and we had to have a meeting. R emphasised the point that she couldn't trust me anymore and I pointed out that C wanted me to say it. We left it at that and ignored each other ever since. 

This has left me questioning 'Am I the asshole?'
So am I?