Again, you see what you want to see, and hear what you want to hear.
The play clock runs down from :40, like it normally would. The referee begins to make an announcement at :24, then at :21 the mike comes on, and you clearly hear him say "down by contact, prior to the ball coming out." They show Tomlin talking into his headset at :15, then he throws the challenge flag at :13, and the play stops at :11.
So at this point, it would appear Tomlin is challenging the fumble based on what he heard the ref say, not some mythical fake challenge to stop the clock.
Yes, the Steelers broke the huddle a bit late, but so had the Patriots. By the :11 mark, Sensabaugh is up top on Gordon, Sutton is on Hogan, Edmunds is on Edelman, and Haden is on Gronk.
You're grasping at straws with your theory.