IF there was a policy on mobs you killed still being the host loot, which I doubt because every player counts and as a host I would gladly take someone running keys/bosses/etc.
It would also not be acceptable to force your leeches to simply run when they could kill the singular target chasing them, or let alive preventing their safety ... however if they have a statement against it, welp guess your just out of luck
Would read something like : "while leeching, if you are unable to stay alive, please notify that you need the clear-er to kill the monster chasing you, in no case should a leech ever kill a monster in chaos!"
overall, it is unlikely anyone would join a game with such rules, but if you did, guess we live and we learn.
However, if it was a standard series of choas runs, with just "dont pick up loot" , and he was accepting nonleeches ( ie boss / key farmers ) , then it goes without saying that rule has unwritten conditions and kicking you out of the runs over you picking up loot from a monster that you killed is quite frankly unfair.
Again, if he was only accepting leeches .. then well I don't know what to say, you have nothing going for you, he is a jerk and abusing the situation to take your FG, and attempt to get you flagged with a warning %
IT is most likely the 2nd case, but honesty everyone in the thread understands that if you kill a mob you get the loot, so there should be a bolded statement / disclaimer about loot in chaos EVEN IF YOU KILLED THE MOB in the original post for the runs, and if there is not one, then at the very least I would say he scammed you of x/y * z ( where x = runs joined, y = runs promissed, and z = FG paid )