Other mistake: Ben brings Emily home from the hospital and Duke is in the back seat. When Ben stops and puts the car in park you can see in the background that the car is still moving.
Other mistake: Ben goes to meet a friend in Social Services. On the door, it says "Sevices."
Other mistake: When Ben is in the car with Emily, they pull to a stop and Ben shifts the car into PARK. However, the car is still visibly moving.
Answer: He is stealing his brother's identity as an IRS agent to research the people he wants to help.
LorgSkyegon