McIlroy is a 21 year old. He held up well through is first three rounds. Today, the 4th round, was the test. His youth and inexperience showed. That's not a choker, that's a young man being tried beyond his capabilities. I can't say how he'll factor what happened into his development, but I wish him well. I hope he comes back and succeeds. Look at Dustin Johnson for a lesson on that...
Shooting 80 while in the lead at one major, you can chalk that up to youth and give him a pass. Do it twice, as he now has, and he is a choker. No doubt about it. It is now up to him to prove he is not a choker.