Around 4:15 into the episode, while Olivia is watching Ellen get into her husband's car, a man comes out of the doorway behind Olivia. The camera then cuts to Ellen being driven away in the car. When they cut back to Olivia, they reused the same footage of her watching Ellen get in the car and the same man waking thru the doorway behind Olivia. You can tell for certain, because that man makes the same exact arm movements in both scenes.
When giving Olivia and Amanda details of her assault, Karen calls her attacker Bob, a shock jock, by the name Mitch, Karen's husband.