He can't get her back. Even if he does get her back, it WON'T be the same. There will be something off about the reunion that he won't be able to put his finger on. She will seem a little distant, a little preoccupied with her thoughts and emotions. Her love for him will seem a little forced.
That something missing will be the attraction in the relationship. When a girl says "let's be friends" it means "I'm not attracted to you anymore but I feel guilty because of this and don't want to hurt your feelings."
'No contact' works to create feelings of missing someone but not much attraction. Time distorts memories and no contact will allow her to gloss over the real reason why you both broke up.
Here's a video that explains that situation perfectly :
"How to Break up With Your Girlfriend in 64 Easy Steps"