I just went in this qa server, and saw both of these people have MC beside their names?
Here's a screenshot

multiclienters, the same person using two different accounts with two toribash programs open, it's quite believable if they both are from the same country, as noted in the flags

That explains why the other one quitted just when I went in the server, I'll send this report to a gm, thanks for the info.

just a heads up :

some multi-clienters aren't the same people all the time.

If I were to go on a server and my brother go on a server (2 different computers)

it'd call us MC'ing.

it just means they have the same ip

Well he said that one of them quit when he went there, so I would assume it was the same person, trying to hide the fact that he was probably farming.