@MoS don't know who Stewart Lee is or what he give Ajaye shit for -- is this from the Green Room ep you mentioned?
Stewart Lee is an amazing British comedian. He's not terribly well-known here, but he's very well-known and well-respected in England. Maron interviewed him on one of the road editions of WTF. I don't think he's appeared on Green Room. The incident happened on his British TV show STEWART LEE'S COMEDY VEHICLE. From Wikipedia: "On his stand-up television show Stewart Lee's Comedy Vehicle, British comedian Stewart Lee mocked Ajaye's LP I'm a Comedian, Seriously, sarcastically questioning the track titles of "Homosexuals," "Girls With Big Breasts," and "Dick Caught In Zipper," in the context of the claim on the album sleeve that Ajaye was a deep thinker."
I haven't seen that episode and I'm not familiar with the Ajaye standup in question. It's more that I think it's funny that Lee is willing to mock fellow comedians by name in public (he's not shy about mocking Russell Brand, for instance), which most comedians avoid out of professional decorum/the desire to work/survival instinct.