Morkus from Orkus
In my group I was given the joking title of "Rules Lawyer of Justice". This is because while I have rules lawyered on my behalf and others, just as often it was on the DM's behalf (including times that it went seriously against my own interests).
However, I recognize that in the end the DM's word is law. Admittedly, in my younger days somewhat less so.
For many years I held a similar position. I had a reputation for coming up with the right rule, even if it was good for the DM and bad for the players. Eventually, the DM recognizing that I was being fair and impartial with what I came up with, flat out assigned me the role of "rules lawyer" for the group. Whenever a situation came up that he wasn't sure about, he'd call on me to get the answer while he moved on to something else.