O.J. Simpson's Lawyer Blasts Stephen A. Smith ... You're Insane If You Think You Could've Convicted O.J.

Stephen A. Smith is DELUSIONAL for claiming he could've done a better job than Marcia Clark at prosecuting O.J. Simpson ... so says O.J.'s former lawyer Carl Douglas.

Douglas -- who was a key member of Johnnie Cochran's legal team -- says he heard Stephen A.'s statements on "First Take" ... and says, "It's one of the least intelligent things I've ever heard uttered from his mouth."

Of course, Smith confidently claimed, "If it was me [prosecuting O.J.], there's no way in hell Johnnie Cochran would have beaten me with the evidence that they had ... I'm not even a lawyer."

Now, Douglas says he loves and respects Smith -- but was adamant, "I don't think there's any chance in hell that he could ever do anything near as talented as Marcia Clark."