Didn't see Bruiser's post, but there's a possibility that when faced with an actual injury, he would have possibly (probably) recognized that while it was a rival, it wasn't anything to be happy about.
I don't know anything about what kind of person CJ is (although his tweets make him look like a piece of ****, or maybe just a normal college student that is dumb enough to not know what thoughts he should share with the public and which thoughts he should keep between friends), and certainly don't have anything for him, but still don't understand gloating over an injury.