Found this interview with UAE DS. Seems like the team screwed up in not telling Del Toro more insistently to change from the original plan (follow Carapaz) and chase Yates.
INTERVIEW WITH UAE DS FABIO BALDATO ABOUT 20TH GIRO STAGE:
“We certainly underestimated Simon [Yates] who was exceptional yesterday. The instructions were to always follow Carapaz, Isaac was good at responding and that’s also good. Simon was smart to go at his own pace and then to anticipate them by pitting one against the other.”
“Unfortunately it went like this. Of course when Simon started to gain 20-30 seconds, having Van Aert in front as a point of support, you were a little worried because Isaac remained on wheel of Carapaz and the two started to look at each other, you know. But in the meantime Simon in front was pushing.”
“When we got to the middle of the climb we tried to encourage him to also take Yates into consideration. We didn’t do it more than once, also because he’s the one on the bike, he knows his legs and his goal was to get to the top and go over the top with Carapaz. He preferred to save his strength towards the end. So, let’s say, in the end it was a decision that Isaac who made his choice by himself.”
“Anyway, it’s an important experience, a boy who was just 21 years old, it’s true, who loses the Giro, it seemed that he could do it by now, but he still arrives second, wins the white jersey, in short he’s a ready to be a champion. Yes, eh, if they had told us after a week that he was in second place, we would all have signed.”
“It hurts him, me, the team, everyone and with hindsight I can say: If I told him one more time “you have to go, you have to chase". Yes, the regrets remain. You know, now it’s easy to do the analyses and give the verdicts. He knew how much energy he had, the legs he had and above all one thing not to forget, young, as you said, it was the first time he found himself on a climb over 2000 m with the best climbers in the world.”
“Only 21 years old and already second in the Giro d’Italia, some will say lost, thrown away, that’s fine. And this is also part of the experience and it’s life and the bike, you fall, you get up and start again for the next race. Anyway, well, you start again with a second place in the Giro d’Italia, well, 21 years old is not bad, anyway. It’s true that we would have signed it before leaving. That’s fine.”