If the shot was such a waste of a chance, it implies that he should have taken the shot anyway. The defender did well to nudge him off balance. The same as with the Falcao chance in the first half, he could also have done something different with it. I don't blame him, because strikers have to strike, and can't score if they can't miss, and they can't assist when they can't take the risk of an intererception. Mata, not beeing a striker, should more often look for the third man and not aiming for the assist or shot all the time.
I don't think it's a coincedence that Villa bounced back from the ropes after Van Persie was taken off, because a lot of his movement makes space for others and he often is there to keep the posession and attacks going.
There's a lot of eagerness here to blame Van Persie, didn't the humble pie of the last weeks go down well and now it's coming all out again?