He confirmed by himself that he forgot to eat (and I belive him looking at his later performances). When you're bonked you can do nothing more.
Don't forget about Zoncolan as well..
Honestly without the hunger knock and the time loss by having to drop back twice, he'd be right up there with Bernal in 2nd place, and possibly the favorite with the ITT looming. No wonder he was angry at the time, at least knowing he had this kind of performance in him.
Today he was simply the best of the GC riders and hopefully the next team he goes to will have good support for him.