how about an option for bad coaching?
it's obvious that rackzo can get webb to run fast in time-trial conditions, but in reading webb's post-race comments, it doesn't seem like coach or webb had much of a plan for the final. webb says something like, well, i went out in last in the semi and that didn't work, so i figured i'd go out in the lead and that didn't work, as if he was just winging it.
umm, shouldn't he have had a better idea of what he was doing and why his training has prepared him for that? read lagat's comments and see the difference his coach made, in making him calm and giving him confidence in his plan.
imho, there is more to caoching than getting someone to run fast workouts. it's about peaking, coming up with a gameplan, giving your runner confidence, getting him in the best physical and mental state to win.
of course, webb could go on to win olympic gold and have all sorts of medals when he finally retires. but you have to ask the question, with a different coach, would he have been more successful when it really counted? and if he doesn't have the career we expect him too, will his ultimate limitation have been his coach?