I can say it because that is what he said and he was playing not you. Andy said he pressed too hard on his shots when he should have played patiently and kept the rallies going. He said it was ridiculous to say that he lost the game because of one point and it is ridiculous to say that. He lost it because he did not move as well as he can (an injury probably but god help him if he mentioned it) and because he decided to play too aggressively in the second set instead of wearing Nadal down. It would be interesting to know how many of the long rallies were won by Andy in the match. He got his tactics wrong. Nothing wrong with his mind - other players lose to Nadal and don't get pschoanalysed like this.
What did you expect him to say? Concede to the media that he's a mental midget?
It is not ridiculous. Everyone saw it. He missed that shot and then lost 7 games in a row. Do you think that's a coincidence?