Revealing mistake: When the police ring Ashley's phone, we catch a glimpse of the screen as she answers it. The phone is not in call mode.
Through a Glass, Darkly - S5-E14
Revealing mistake: When Jason shows Ali the family photo you can see that Jason and Ali have been badly, almost cartoonily photoshopped in.
To Plea or Not to Plea - S5-E22
Revealing mistake: When Emily calls Varjak's number from the Tony's Pizza receipt, her phone says that it has no service - meaning she should not be capable of making any calls.
The Melody Lingers On - S5-E23
Revealing mistake: When Aria calls Spencer after the first trial scene, Spencer's phone is not in call mode.
