Brain Wash - S3-E8
Continuity mistake: As hairdresser Bob is washing Jamie's hair in the sink, the shampoo coverage changes between shots. During the closeups, he never touches her forehead and ears but in the wide shots, her head is completely doused.
The Pyramid - S3-E13
Revealing mistake: As Jaime starts 'cutting' along the window with her bionic fingernail, the precut outline is quite visible from the sides, and her left hand is resting on the ledge of the first hole she cut, to give her leverage. Which would be impossible for her to do, as it's raw glass and would leave bleed marks on her hands. (00:34:30 - 00:35:20)
Revealing mistake: The wires holding the small satellite the two alien men are 'channeling' across the lake are visible although it's supposed to be floating.
Continuity mistake: The hole Max makes in the wooden gate changes in shape when the thugs reach it. Max crashes through, leaving a hand shaped hole, but as the thugs reach it, the 'thumb' has disappeared.
Revealing mistake: After Max the dog breaks free from the cage and then bites through Callahan's chains, the two head to the metal barred window and Max begins pulling on one of the bars with his teeth. Which are obviously rubber, as they 'bend' slightly as the dog is pulling.