Thing that impressed me with that attack is he really, really buried himself just when everyone was looking around/at the moment of indecision with riders still thinking, hesitating, not sure.
...and Evans must have known he had a chance to TT to hold to finish. Others may have been betting they could bring it back. Wrong guess on a guy who can climb AND TT.
He held no cards in reserve while others were shuffling their decks.
That attack was a Hinault-like attack...No question about it.
(Yes, it seems Cunego was out of position).