Rules lawyers, to me, are usually fairly benign and I can see how people see it as a neutral term. And, really, no DM worth his salt should ever be annoyed at being corrected when he's outright wrong. When the player can point to the book and say, "No, this isn't right" and the DM simply over rules the player, barring standing house rules that should be known up front, the DM should have the good grace to stop and fix his ruling.
Now, if its a case where the ruling could have more than one interpretation, the player shouldn't bog the game down either. Getting through it quickly and as painlessly as possible is the goal of any rules questions.
The problem seems to come when ego starts to enter into the equation. There are some DM's who get all huffy when a player has the temerity to question his judgement. Me, I've gotten over that.
What truly does annoy me though, is someone who thinks they're a rules expert but isn't and, despite being corrected time and time again, still insists that he or she is a rules expert. If you don't know, but you think something is wrong, LOOK IT UP FIRST before arguing with the DM.