Touched by an 'A'-ngel - S2-E10
Revealing mistake: At the end of the episode, Emily receives a phone call from Dr. Sullivan which she does not answer. Look at her phone when she hangs up: Not only does she simply press the "hang up" icon when the arrow indicates she needs to slide it to the left, there is also a magnifying glass symbol at the bottom indicating that it is in fact an image file on the screen and not an actual phone call.