Sounds like the hype and expectations got to him a bit and/or perhaps he thought it was going to be easy. Running fast is never easy.
"The strategy was to run hard at a 4:30 pace. I had that for the first mile, but I didn't feel comfortable. I just didn't have it. Once we were off pace, I really wasn't excited out there. No one runs well when you're not excited.
"I was faster in my half-marathon than the record here. If you can run that pace for 13 miles, than you would think you should be able to run it for nine."
from:
http://www.jacksonville.com/tu-online/stories/031107/spl_8536413.shtml