The standards of professionalism predate me, and while they may vary slightly between organizations and individuals I think most people would come up with a pretty common set of standards that an admin should follow.
I think most would agree that civility and fair dealing are desired from an admin staff.
I think most of us would agree that admins who take cheap shots at people in sanction threads don't meet those standards, even though most of us can recognize that it's probably fun to do so.