Visible crew/equipment: During the doctor's office scene, when Larry walks over to pull the paper across the bed you see beige directors tape on the white rug in a distinct "T" shape instructing Clive Owen (Larry) where to walk.
Visible crew/equipment: At the end of the film, when Natalie Portman stops at customs, look at the bottom left of the screen when she hands over her passport. The bottom half of the camera equipment is reflected in the glass. (01:36:40)
Answer: I think it was because of the offer that Larry made to Anna. He promised that if they had sex one more time, he would leave her alone and never contact her again. The fact that he was willing to give her freedom, is what made her choose him. Dan was more "needy" and pushy, which is hypocritical, because he left Alice based on her being needy.
Dan left Anna after confronting her about sleeping with Larry for the divorce papers. Anna begged Dan to not stop loving her, to not leave her. Looks like Dan could not stand Anna after she slept with Larry so she went back to Larry since she never turned in the divorce papers.
But after the incident, Dan went to Larry's office and begged him to "let" Anna return to him.