For every group that is not your own that hits an Inquisitor in the Halls of Atonement, you lose 1/5 of the rep down to 0 rep. This means that if 4 random people run up and hit your Grand Inquisitor it is now worth 0 rep.
This was happening to our group last night. Very frustrating when a random player(s) runs by and thinks your Inquisitor is a rare that could drop them a mount or something so put a dot on it and goes to do something else while your group finish killing it. They hadn’t even unlocked the rep yet.
To add some more detail to this. It’s not strickly 1/5. It’s 20.
Normal inquis are worth 50 rep, so 3 other people tagging it negates the rep.
High inquis are worth 100
Grand inquis are worth 200
High inquis I haven’t played around with much.
Grand inquis on the other hand seem to be coded to give full rep up to 5 people to whoever/group summoned it.
I was in a group earlier of 4. If we summoned a grand and one person tagged it we still got full rep. Anything more would decrease it by 20 per person.
Additionally, I thought this might be an intentional change on Blizzard’s end to prevent a bunch of groups stacking on the mob and sharing tag/rep. However, I was talking to a person who tagged one of our kills and he let me know that he got nothing. No rep.
Since he got nothing and we got penalized, something doesn’t add up. This is either an oversight or a bug.