One final showdown. How much money did NFL pay that scrub Steelers RB to fumble an easy ball ON THE LINE FOR A FIRST DOWN? Of course the Broncos take advantage of it.
Did the NFL want Manning vs Brady? Absolutely (ratings bonus).
Would the NFL exact control within their administrative means to make business favorable outcomes happen? Absolutely (anyone who thinks they wouldn't attempt to gain favorable business outcomes is foolish).
Does the NFL want to see the Patriots lose to Manning? Umm, probably (tough call as the NFL certainly is not against the evil empire crashing and burning at their biggest show. Remember, the NFL gets to setup good vs evil as they will remind everyone at the right time of their evil ball deflating. But to send their golden equine out on top? That's the kind of PR that is hard to buy -- being able to make a group of scammers look magnanimous, swell and righteous by honoring the 'good' guy.
But IF the Patriots do beat Manning, do they want to see them lose to Cam Newton? 100% Absolutely (NFL wants a filled pipeline of marketable stars to backfill the old guard as they drop off. They want the next Manning vs Brady).
With that said, the NFL did not pay anyone or direct anyone to fumble. It is almost silly to suggest it. The NFL is not and will not be providing a briefcase of cash to any player or ref as a quid pro quo. Even for the impunity based echo chamber full of these egomaniacs they absolutely know there is a line even they cannot cross. If that kind of thing came to light it would be a massive scandal that would tangibly impact the NFL's bottom line, the monetary ripple effect across media could be enormous, and it could possibly lead to criminal indictments.
But this is not to be confused with the NFL using its administrative authority to exact some control over games. Using their power to give 'friendly' pushes in the right business/ego direction is something they have and will do. Hell, arguably they have the full legal authority to do so. It's unethical but it still is probably ok otherwise.