The Colts already expressed they don't care about records. Believe me, once they get guaranteed homefield advantage, they'll rest their starters. Thus it's pretty much impossible for them to go undefeated unless Jim Sorgi suddenly got amazing enough to overcome their terrible run defense like Peyton is.

On your other point, the Chargers have a good defense, Carson Palmer was just a man on fire. Though, I don't think I can say the same about Cincinatti. When the Broncos lost to the Colts in a shootout, it didn't make me doubt the Broncos D any. Peyton is just a beast and they didn't pressure him enough. No matter how good you are, if a good QB has time, he'll find cracks. I think more credit ought to go to the O-Line of the Bengals for blocking an impressive front seven (even without Merriman) quite effectively.