As you said, "albeit possibly using 3rd party tools", I'd say they are no longer legitimate players at that point, and them being there to respond really means nothing else than that they were around there at the time to look and respond (or/and were alerted to the /tell to respond to it).
Of course they will be monitoring the thing at some points in time, but all the actions could still all be automated, no matter what a GM says. The game would need to use an intrusive anti-cheat method to see what you are running to detect things, and I am very happy it does not right now. Not because I run anything funky myself, but that nonsense is basically what rootkits and malware and such are, and I don't need them in my system (they also don't play well with Wine due to the intrusive reasons I mentioned, and I use that to play the game on Linux).
I think I commented here before, that this definitely might not be the best way to do things, and not how I'd do it, but I do like it that someone is highlighting this problem which is very real.
Funny(?) enough, I've thought of writing a script to report certain long-lived bots automatically, because I've been reporting them for years manually... but I still want to do at least minimal verification and such on them. I did see some bots disappear eventually, but I imagine they just got what they wanted, and/or moved elsewhere.