I never said NFL games had been fixed, just sports events at very high levels (MSL baseball blacksox, Cleveland State basketball, Boston College b-ball to name a few); why would you believe the NFL would be somehow exempt from that? The mere fact the NFL referees are completely screened from public/private scrutiny (as poster Diplomat correctly stated), would make it all the easier for dirty refs to ensure an outcome they wanted. Players and coaches who even hint at official malfeasance (except Pittsburg's Joey Porter... SURPRISE!)(Not), get fined or suspended. Media types would be banned from press conferences for suggesting such a thing.
As far as your example of the helmet to helmet hit, even in real time it looked to me like the defensive back hit the receiver in the back, not the head. Replay clearly showed it was a legal play, and that is why the flag was picked up, it was not a very close call. In fact, that is another example of a questionable call being made against Seattle.
I'd challenge you to name even 1 crucial (crucial = game changing or took points from the scoreboard) call that went against Pittsburg. I can name several that went against seattle, and have already done so.
The superior teams can overcome this kind of routine stuff. Against the Colt’s, the Steelers still found a way to win despite being denied a game-closing interception (and unlike the 'Hawks they got an apology from NFL because that call was actually incorrect).
Prime example from SB XL: Steelers have a first and 10 at the Seattle 22. 1st down incomplete pass. 2nd down 5 yard completion – OMG! a phantom pass interference call on Heath Miller. Did you see the pass interference? I didn’t. If Madden and Co. had beefed about it the public would have bought it hook line and sinker. 2nd down (repeat) Wistrom sacks Roethlisberger bringing up 3-28 at the SEA 40. Out of field goal range. Adversity. Did they fold like Seattle? No. Instead a great play results in 1st and goal.
In the AFC Championship game Bettis hit a great 10-yard TD Run which was called back on an obscure Hines Ward illegal formation penalty. Did the Steelers fold like a cheap suit? No. They came back and scored another TD with a pass to Hines Ward!
Are you aware that OPI penalties have actually been called in past Super Bowls? i.e. against NE/Troy Brown. Unlike the Seahawks, they shrugged it off and won the game anyway.
Unfortunately, a great percentage of the newbies watching the Super Bowl don't understand that the commentators and analysts frequently have no clue what they are talking about and that they have biases just like other forms of media. So the sheeple will hear Steeler haters make definitive assertions and buy it unquestioningly.