Continuity mistake: As Trent and Lionel talk, while Lionel is in the hospital bed, when the camera is behind Trent his shoulder and neck are barely illuminated and is in shadow as the camera is looking down on Lionel. When the camera is looking up at Trent, even though he has not moved, his shoulder and neck are now brightly lit and shows no sign of a shadow.
Continuity mistake: As Lana and Lex are talking, as Lana says "Actually, umm, I came by because.". In the middle of her going "umm" there is a camera change. Before the change Lana has her right hand on the arm of the seat. After the change she now has her right hand scratching her head.
Continuity mistake: There are several close up shots of the syringe that Dr. Hamilton is using to threaten Pete with and you can see that it is made of plastic. Clark uses his heat vision to overheat the syringe causing it to burst but the sound the syringe makes when it bursts is that of a glass syringe and not the plastic one he was actually using.
Continuity mistake: When Clark, Pete and Chloe were looking for Clark's father in the woods, Pete says: 'the twister must have dropped it here' and we see Chloe holding the map in her right hand. Cut to a different angle (as Clark runs towards the screen) and in the background we see Chloe holding the map with her left hand instead.
Revealing mistake: At the beginning of No Mercy - Season 5 Episode 19, Lional's limo comes to a screeching halt on railroad tracks. The camera is panned out to where you can see this happen. The black tire marks that are supposed to appear from the hard braking are already present, which means there were multiple takes.
Character mistake: While Clark and Chloe are at Daily Planet, Clark asks her what is wrong with her mother. Chloe responds that her mother left when she was twelve years old. In the episode Lineage, Chloe and Clark are looking for Rachael Dunleavy and Chloe says her mother left when she was five.
Continuity mistake: Just before Lex has his father arrested they are talking while Lionel sits behind his desk. In the shot of Lionel from his side of the desk there is a flat panel monitor behind his keyboard. In shots from Lex's side of the desk the monitor is gone. It returns as FBI agent Loder walks in and Lex stands up.
Continuity mistake: After Clark gives Chloe the piece of paper with the list of cars that checked into the hotel, Chloe holds the paper in front of a folded up newspaper. Between shots, the newspaper turns the direction it faces. Then in the next shot, Chloe is only holding the piece of paper, and the newspaper that she was holding behind it has now disappeared.
Revealing mistake: In the early scene with the baby, there are a few overhead shots of the parents and child. It is clear that in these shots a fake baby was used - he is completely motionless, even though he was moving arms and legs before and after and is crying. (00:02:00 - 00:03:15)Phoenix
Plot hole: When Edge needs the vial of Clark's blood back, Edge holds Clark's parents hostage. Clark decides to use a sharp piece of kryptonite rock to cut his skin and give Edge a new sample. When Clark picks it up, and when he places the kryptonite rock on his skin, he shows no sign of the usual effects of the rock which include the green lines radiating up his arms.
Continuity mistake: The meteors are shown traveling together in space at the beginning, but the smoke trail from the first meteorite runs perpendicular to the flight of the next one. They should be falling along roughly the same flight corridor, as all the other meteorites do. (00:00:10 - 00:04:30)Phoenix
Continuity mistake: Lex's aide is shot in the back as he makes a run for the door. When he goes down he slides head first almost all the way to the door. A few moments later, just as Flynn shoots out the security camera, in the security monitor image Lex's aide is now in a different position.
Revealing mistake: As Sheriff Ethan pulls up there is a reflection on his driver side window. You can see the police department shield on the door and the door handle reflected on the driver's side window. There were no other police cars there so it was probably reflected off a mirror used to help light the scene.