Continuity mistake: Norma reaches over to touch Chick's walking stick with her right hand, but the next shot shows her using her left hand.
Factual error: When Dylan gets a call on his cell phone, it's from an 8-digit Costa Rica number, but caller ID shows +1 506 2555 0122. +1 is the US international code.
Revealing mistake: The open eyeballs of Norma Bates' corpse move as Norman holds her head in his hands.
Continuity mistake: In the V.I.P. room of the strip club, the dancer straddling Norman stands up. In the next shot shown in the mirror, the dancer stands up again.
Continuity mistake: When Alex shows up at his house to pack some belongings, he finds his ex-girlfriend Rebecca already there. As Alex and Rebecca talk, the camera pans back and forth while conversing. Alex's jacket is stuck behind his name plate in one shot, then the name plate is completely covered in the next shot. This occurs multiple times. (00:26:20 - 00:27:40)
Refraction - S4-E5
Continuity mistake: When Chick delivers the window he uncovers it. When he leaves it is covered, then uncovered and recovered again.
Continuity mistake: When Dylan confronts Norma with the earring of Emma's mother, he is holding it aloft in his right hand. Shots from Dylan's right rear and his hand is at waist level, the next shot from the front and it is held aloft again.
Revealing mistake: Norma is driving her car as landscape and cars traveling opposite her flash by. In her driver side mirror, there is no reflection of the cars passing by, the road, or any landscape. The mirror is blank.
Unfaithful - S4-E8
Continuity mistake: From her left side, Norma is fiddling with her wedding ring while lying in bed with Norman, but her hands are separate in the view from her right side, then playing with her ring as the shot switches back to her left side.
Continuity mistake: After Chick leaves, Alex approaches Norma with his arms outstretched. The immediate shot from Alex's rear and his arms are at his side.
Continuity mistake: During Norman's hypnotherapy, he remembers approaching his Dad as he is passed out on the table, and his Dad's right arm is at his side. As Norman comes abreast of his Dad, his Dad's right arm is now on the table.
Continuity mistake: When Alex meets Rebecca in the restaurant and slides her the key, her hands are down. The immediate shot after and her right hand is holding a cup of coffee.
Continuity mistake: Norma's hands change from clasped to unclasped several times as she is speaking with Dylan in the Bates house.
Continuity mistake: Once Chick leaves after unveiling the stained glass window, the protective packing keeps moving position between shots while Norma is speaking with Alex.