McCourty was flat out awful in the 1st quarter. 1st quarter 5:15 mark got beat deep on a seem pass to Thomas. Simms went onto say that Denver knew they could hit this play due to watching film and they picked up on McCourty tends to be late and often out of position. He tended to be late in Colts playoff game and let up two long TD's. Not my words they were Simms.
Based on my amateur knowledge of coverages (and somebody can feel free to correct me if they think I'm wrong), that play looked exactly like what people want to do with Revis. It was a 5-man blitz, and the four DBs (other than McCourty) plus Collins each had man coverage on a receiver. But more specifically, it sure looks to me like Talib was on an island, with McCourty playing more of a deep half on the opposite side, something like...
(Blus is coverage, orange is pass rush. The DTs cross, and then Hightower goes up the middle between them. There's no good way to draw that in Paint.)
Now there are two main reasons that I came to this conclusion. The three guys on the offensive right side all engage their defenders at the line. Talib doesn't. He goes straight into his backpedal without any attempt at a jam. A few moments after the snap, the coverage looks like this:
One of these things is not like the others. The three defenders on the offensive right side are jamming their receivers. Talib is not. If my thinking on this play is correct, that's because Talib needs to respect the deep ball more than the other defenders. They have McCourty backing them up, while Talib does not. And then...
There are two things happening in this picture. First of all, notice McCourty's position. The term you hear a lot is the "rotation" of the safeties. When the SS comes up in a shorter zone or in this case man coverage, usually the FS rotates more toward the middle of the field. There's no rotation back there. From the snap to when McCourty makes his break toward Demaryius Thomas, he's gone basically straight back 8 yards. Again, feel free to correct me, but I would think that if McCourty had any responsibilities as far as helping Talib, then he would at least made some movement toward that side of the field.
And of course, the other thing to notice in this picture is Talib. He's facing outside while his receiver flies by on the inside. Yes, I understand why Talib bit so hard on the fake outside. If Thomas beats him to the outside and Peyton delivers a good ball, it's a TD. At least by funneling Thomas inside, it was only a 29 yard play (and eventually a field goal) rather than a TD. Still, I think that's the biggest difference between Revis and Talib. Talib did a lot of good work singled up on some good receivers, but I would expect that Revis makes this kind of mistake a lot less often.
At least from my point of view, this wasn't at all McCourty getting beat down the seam. It was McCourty cleaning up Talib's mess. They were asking a lot from Talib on the play, and he couldn't do it. I think the announcers completely over simplified things, and unfortunately most people aren't going to give it any second thought.