I'm confused about this part too. I thought he convinced her he had to give the money to the partner to save their lives. She left, he pretended to meet the partner in the car, she drove off. He can back in the house, got the money and left.
Don't know for sure....I didn't tape it so I can't re-watch.
ETA: I thought he might have left himself open to be able to follow her to the motel. Maybe another flashback...
I'm editing again.... SEMI-SPOILER ALERT
http://www.tvguide.com/News/Ausiello/AusielloReport scroll to bottom of page