My recollection is that in 2008, he was pitching hurt to some degree. They didn't know if he was going to be able to start Game 6 of the ALCS, and it was obvious he was struggling, but he pitched 5 innings and got the win.
As I said to Kimmi earlier, I don't believe that clutch or choke are something pure and undiluted. I think it's more a belief that some guys are more confident or comfortable under pressure. Maybe the confidence factor comes from getting off to a good start in your postseason career. That would apply to guys like Schilling and Beckett. And we know that the postseason thing was a big burden on Price's head, and Kershaw's as well.