I've had several cases today where I wanted to Punish someone other then the reported player.
However, odds are, players like that are going to be reported, if not in that game, then in other games. If it's so bad that you wish you could Punish them, other people do too. Not only will they get reported, they will get reported alot. And you've already seen that their chat for just the one game you managed to see was Punish worthy - so it will be again.
The Tribunal will find them and take care of them. If not, well then, that means they were just having a bad game, or decided to reform without Tribunal intervention, and in either case, they don't need to be Punished anymore. But that's probably not the case, and either way Justice is served.