He did alright coming in and made a couple of decent saves, but they weren't anything I wouldn't expect him to get. Even the one from the header just outside the six yard box wasn't hit that hard. If it was Howard they'd be called routine so it's the same for Robles.
He still looked terribly unsure at the half dozen corners they had in the first half. Apart from one where he was blocked in he came then changed his mind and tried to backtrack again, if a Norwich player got a decent head on any of them he'd have been caught on the back foot. Even for their goal he came, didn't make it and never got properly back on position before they scored. He was nothing special, even the penalty save was a fairly easy save as long as he went they right way.
No penalty save is routine.
He was a little over-dramatic at times, but you are probably down playing his overall performance a bit too. His save of the header from six yards out was less routine than you make it out to be, and I just watched Norwich's goal again, and he was not out of position when the shot was taken.
I understand you are trying to manage expectations since he did not actually have a blinder, but it was a very solid performance overall, and certainly encouraging.