Sounds like a perfect opportunity to report someone and have it count for more, since they said in the chat log they were going to do something thats prob against the ToS and then they did it. I don't report people much, but the times I have it was either for flat out racist speech in alliance chat or someone intentionally wasting everyone's time in a way that can be objectively proven. There are some people like that, on very rare occasion, where it's not just a matter of me disliking them, but goes far enough that I think we'd be better off not having them in the game, and that's SE's decision and not mine, but if there's information that might help them reach that conclusion I'm happy to share.
If someone logs into a trial fight and just stands there to leech the rewards for example, can't objectively prove anything like an emergency didn't make them have to AFK. But if they're walking around doing /laugh, /wave, /sit, etc while the rest of the people do the work, that at least shows it's intentional (and it's probably not like they woke up that day and decided to be a total troll for the first time in their life so they probably have prior reports on their account which I hope get taken into account with each new one but who knows). It might be my imagination but the two or three times a randomly composed party from DF and I agreed we were going to report someone after the instance, seems like the response came back a lot quicker and I wonder if someone getting reported by a lot of users from different servers at once, for the same violation, sets off an alarm- but that's just conjecture on my part.