While Zeballos played really well and showed no sign of mental breakdown, Rafa did get tight at 4-5 when he ended up losing all 3 points giving Zeballos a 0-40 lead!

It happens to all of them.
You are right, some people are bit too hung up on Andy losing and contributing everything to choking whilst it's not the case each time
To quote John McEnroe - "Players choke all the time, only some do it more often than others", and Andy certainly does not fall into the latter category.
Like sh*t, eh?
Except Robbie doesn't need anything to get him going.

Having just watched Nadal defeat the world #140 Joao Souza (the Brazilian player, that is - not the Portuguese Joao Sousa that Andy played in the AO) 6-3, 6-4, I'm inclined to agree with him too. As the comm said during the 2nd set, "Nadal's mystique has gone".
Souza played a reasonably solid game, helped by some very good serving, but Nadal would have lost against a better and more experienced opponent. The fact is that these guys are no longer going to fear Nadal and so will just go all out because they have nothing to lose. Souza never looked fazed, but Nadal, whether or not it was the after-effects of Chile, seemed nervous (the bum-tugging was well on the go, which is always a bad sign) and his movement round the court was sluggish.
I don't under-estimate Nadal, but, as I see it right now, unless he improves dramatically by the start of the clay court season and gets his confidence back, then his chances of meeting Andy in any of his tournaments look somewhat remote.