Unfortunately, being heard and seen is the way to be thought of as productive - both in RL and WOW. I completely understand why you're upset, I would be, too. Regardless, if you turn your back on the raid group, you'll be labeled as "the guy who didn't like competition", or worse "the guy who started breakup of the raid". Remember, you've been in the raid group because all of the folks play well, and (obviously), you all match well and work as a team. So I'd say it's worth sticking with the raid group and trying to make your RL understand it's the new pally who causes problems.
I'd pull the "teamwork" stunt on him. You know, "he's not a team player", "he places himself above the good of the group", etc. From what you've explained sofar, it's true.. but you need to "sell the idea" to your RL.
Blood ........ Not Funny
(Keyword index of Abyssal caste book, Exalted, 2nd Edition)