Continuity mistake: While trying to restart the engines after the ship is hit by the nuke's EMP, Chandler is checking the fuses while Chung is going through his checklist. There are only five visible fuses in the six available slots in the panel that Chandler is checking. After he gives the order for Chung to "give it a kick-start," the slot which previously had no fuse now does, only for it to shoot out from the start attempt.
Single Point of Failure - S1-E2
Revealing mistake: Walter accesses code on the sick girl's laptop to trace the source of the virus - aside from the fact that the code comes straight up a fraction of a second after his hands even touch the keyboard, the code displayed in the black window is for a set of traffic lights, with lines like "Walk/Dont_Walk" and "Green_Arrow/Yellow_Slow." (00:08:10)
Revealing mistake: When Iris is sitting in bed recording the message for Barry, she is holding her iPhone so that the start button is on the left side, but the "video record" button appears on the right. Additionally, her right hand covers the speaker area of the phone fully, including the front facing camera. It is impossible for Iris to be recording the video live and reveals that the video footage was recorded ahead of time. The illusion that the video is being recorded by Iris live is further ruined by the fact that the room lighting is turned off in the scene, but the recording is well lit. (00:02:55)
The Thing About Heroes - S5-E2
Other mistake: Officer Burgess kicks in a door with a lock and deadbolt and does no damage to the door frame. (00:46:21)