Didn't stop? If he stops playing a rogue, they mean. Okay, I may be wrong on this, but I honestly thought being sneaky and inventive was what the rogue class was all about. Turns out that using their skills to achieve monetary gain is a no-no. Oh wait, what about Pick Pocket you say? Yeah, my point exactly. I fail to see how using the skills programmed into the class is exploiting the game. Yes, he is able to stealth through the instance and collect items from chests. Yes, this enables to rogues to make cash in an inventive way. So does AoE farming fire elementals on the Elemental Plateau. Will this too be considered an exploit soon?
There is a fine line between using the skills your characters have in an inventive way and exploiting weaknesses in the game. A rogue's ability to stealth by enemies? I really hope they don't consider that an exploit. Otherwise why not just roll a warrior and have done with?