If a helper from a team fighting for GC gets into the break, he usually doesn't work and we don't have any confirmation that Nieve was working - he probably wasn't. If Froome wasn't cooked, they wouldn't have needed to bring Nieve back - Porte/Froome/Contador/Nibali would've bridged to the Talansky group. Remember the Tour stage when Contador attacked like 19 kms into the stage (the one with double Alpe d'Huez)? He had at least two Saxo guys in the break to help him as soon as he attacked. On Fuente De stage in the 2012 Vuelta he also had Paulinho attack early on (while Froome had Henao and Valverde had Quintana). Same for Schleck when he attacked early on in the Tour, IIRC Monfort was up front. Having a teammate in the break can prove very useful, if you know how to play your cards. (Froome isn't a tactical genius, neither is his DS - but perhaps they're learning.)
That or I'm completely wrong and Sky knew that Froome is cooked so they decided to send Nieve for a certain victory. Don't know if you've noticed but when Nieve wins, he always picks the hardest stages (Gardeccia stage in the Giro, Cotobello stage in La Vuelta).

Indeed Contador should've followed Nibali and Wilco, together they would've made it. Perhaps he was in Pantani mood Jokes aside, it took him too long to realize Froome weakness, if Froome was any good Nibali's move would've been suicidal with two Sky helpers still in the group (Contador had more to lose). At least it made for a better spectacle. And it's kind of nice that Talansky won, even though Contador has never won the Dauphine, he'll get his maillot jaune in a month or so Or not but this win wouldn't be such a big deal for him.

Good to have Contador back because Froome is simply boring. It's not that he isn't aggresive though he's no Contador when it comes to long-range attacks or unconventional moves. But he's a bit like an ugly version of Rodriguez (in the sense that he's last mountain guy) and by ugly I mean his riding style that pains the eyes. And the fact that he came out of nowhere is pretty unnerving. Also while he seems to be very good at looking at his power meter, he isn't so gifted when it comes to reading races (he's always superior thanks to better team and sheer physical strength). Plus judging by his book and things he wrote about Wiggins and especially Contador he's arrogant - I guess calling Contador lazy just bit him in the a**.
Compare all of that to Contador who attacks uphill, downhill, even on the flats and though he sometimes wins because he's by far the strongest (Verbier, Etna), he's also able to find the way out of difficult situations (Fuente De) or at least tries to do so, entertaining us in the proccess (echelons in the Tour 2013, downhills and Alpe d'Huez in the Tour 2011). And he gets into his rivals' heads on the road, not by silly puns.

(Though I hope Froome finds his form back and we'll see a good battle in July.)