This is laughable.
What was he supposed to do that he didn't?
If we revisit the chain of events leading up to their goal:
- Evra is tracking de Guzman, Vidic is on Michu, Evans is on Routledge
- de Guzman played onside by Vidic and Jones as Evra stands waving his arms around outside the box and doesn't go with him
- Vidic leaves his man to try and block de Guzman's shot because he's under no other pressure
- Evans has to shuffle across to track Michu but can't get there in time
- de Gea has to save a shot from a more or less unmarked player 4 metres away from him, struck across him. The shot is hit at hip level and to the side of de Gea - from such a small distance with such a firmly struck shot there's no way he can get his body behind it so there's no way he's catching it
- Michu is ahead of both Evans and Jones as the shot is parried, despite starting from behind them.
But yeah it's all de Gea's fault