Were you angry at Djokovic's pushing after that point, yes or no?It has nothing to do with it being a poor approach shot. It's about superior defense. An excellent approach shot is usually not enough against a pusher like Murray.
When Fed hits approach shots, they aren't "poor". It's just that Murray's pushing is far superior to someone's offense.
http://www.youtube.com/watch?v=0--IBsJA5wQ#t=02h27m30s