Once in the valley whence all is allready lost, yes. But beforehand he wheelsucked almost the entire climb untill they were like 2 minutes behind, on the assumption that Carapaz needs to work and he doesn't, so he didn't cooperate with Carapaz. To think that's smart is really something for me, because he was always loosing the Giro the way he rode, taking away the, albeit maybe small, chance of victory.
Makes little sense to me to say, with hindsight, that this was still the smart thing to do it. I also wonder what Giannetti is going to say after evaluation, because at the finish he said he still didn't know what happend on the climb. Which is pretty amazing to me but anyways.
The saving grace for del Toro to me only is that he was loosing this no matter what in my opinion. They won't catch super fast Yates and they're always gonna be smoked by van Aert in the valley. So whatever his decision was, the main difference is optics. But the optics are very bad indeed, because he looked like a moron, especially with this silly sprint in the end.
Overall he's young, he raced stupidly and he lost a race he was going to loose today anyway. There's stuff to learn from it and in a way it's pretty funny to see UAEs tactics all over the Giro.