Beware Greeks Bearing Gifts - S1-E12
Visible crew/equipment: As the people of Troy are about to be attacked by the warriors in the horse, the camera pans up to the side of the wall where Deiphobus is talking with another soldier. You can see a crew member crouching down behind them wearing a white and grey shirt. (00:30:35)
Revealing mistake: When Callisto holds the chakram with one finger, you can see the stick she's holding that makes it look balanced on her finger. (00:16:20)
Motherhood - S5-E22
Continuity mistake: When Athena falls on the ground after mortally wounded, she was not holding her wound. When her body was shown again, she is.
