Continuity mistake: Season 2, Episode 5: "Goodbye to All That" - We see Marty Bedell playing on his Xbox 360 with a headset attached to his right ear. But when the T-888 arrives at his house to kill him and he goes to answer the door, the headset is gone. There was absolutely no time for Marty to remove the headset as the camera cuts too quickly.
Continuity mistake: When John and Pyle are at the shooting range, John's protective glasses are up on his head when he fixes Pyle's gun, down on his face when he fires the gun, back up on his head after firing and then back down on his face when he gives the gun back to Pyle. They're then back on his head before taking them off before the scene ends.