Can't theses guys recover from a half-marathon in a week. Especially when in world record shape.
Of course they can. He did. But he's still recovering from a world record in order to race against one of the most competitive road race fields in the whole world. No matter who you are or what you've done, a week later you're gonna feel that half marathon.
It takes time to recover 100% from a hard run when you're not using drugs. The drugs have completely skewed perceptions of normal. The old guys who didn't use drugs used to get tired after races and hard workouts. Obviously from the account of the race, he was 98% recovered in one week, but not 100%. They were fast, but they were unaided humans.