This is where you're wrong. I'm not banking on McIlroy to shoot 65 tomorrow, just banking on Tiger not falling too far off the lead heading into Sunday. The odds are going to be about the same for whoever might be leading Tiger; whether it's Ogilvy, McIlroy, Choi, Day, etc..
The moral of the story is don't jump on McIlroy +310 right now if you have Woods to win. The only two people you wager on to win the tournament right now are Rory and Tiger...that's why I used him.