See, here's the problem: You don't know that for sure. You don't know if Tomlin knew the play could or couldn't be challenged, yet you'll go ahead and assume that to be the case, then heap praise upon the guy for his brilliance.
First of all, despite of the insistence of the announcers otherwise, the defense WAS set. The Steelers had a player lined up on every Patriots' receiver prior to that second down play, 4 on the line, and 3 deep.
Secondly, about that "game changing interception"? Umm, that occurred on second-and-goal, SIX plays after the throwing of the challenge flag. You're lauding Tomlin's intelligence for purposely stopping the game and getting " the correct personnel on the field"...for a turnover which happened in a new series of plays after nearly three minutes of game clock had elapsed? C'mon, guy.
Given Tomlin's recent ineptitude in the challenge department, isn't it just as likely that he didn't know the rule? And/or he was just hoping and praying (like he's done in many other indiscriminate challenge situations), that the call could somehow be overturned? That it wasn't some ingenious wizardry highlighting his advanced in-game football IQ?
Truth is, we just don't know.
People who blindly love Tomlin will always see what they want to see, and bend the truth for his benefit. He's no idiot -- he's been smart enough to con his employers with not much more than the use of smoke and mirrors right from the very start.