I don't think Tony has some secret magic technique off his back. Once he's on his back, he either solves the puzzle or gets Smeshed.I don't think Ferguson will try to get up and just fight from his back which is not a bad idea considering how Fedor got caught by Werdum, off of his back and Cain got caught by Werdum, back against the cage.
And I think Khabib has already seen everything that Tony is going to try...although this is one of those times it'd be great to be wrong.