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: 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.
Continuity mistake: When Clark first finds the necklace in the shower drain it is all in a single line with no loops or overlaps except at the very end. As Clark picks the necklace up it now has several loops and overlaps all along the chain and not just at the end where the clasp is.
Continuity mistake: Jonathan reveals the kryptonite to Clark/Dawn and Clark starts to react to it. Because of the kryptonite Clark drops the tiara he took from Chloe and it hits the floor near Chloe's hand. Then, just before Dawn is forced out of Clark's body, the tiara has slid several feet away and is now close to the furnace. Clark turns his attention to Chloe, she is faking an injury at this point, but now the tiara has moved back to be near her hand.
Continuity mistake: In the barn loft evil Lex has a kryptonite ring in a lead box. When the camera is in front of Lex he is holding the box so that the lid is pointed towards his thumb. When the camera is behind Lex the box is turned so that the lid is pointed towards the end of his fingers.
Continuity mistake: As Clark and Geoff are driving, the first shot of the SUV as it comes around the corner shows the ground is wet and the wipers are going. During their conversation the windows are constantly being rained on. Geoff points to the stadium and they arrive a few minutes later and as they drive into the garage you can see the street is dry.
Continuity mistake: After Lois and Clark find out that Cooper dies, and after Lois leaves, while Clark and Geoff talk about how Lois is trouble Geoff hair keeps going from neat to slightly messed up. When the camera is behind Clark, Geoff's hair is all shaggy on the left side of his face. When the camera is behind Geoff, his hair is fixed so that the loose strands are tucked behind his left ear. These changes repeat throughout the scene.
Continuity mistake: During much of the conversation between Clark and Lana, while in the caves, you can see the cave painting that matches the tattoo on Lana's back is behind her. Then, towards the end of the conversation, she is still standing in front of Clark and during the scene has not moved from that position yet, once she sees the cave painting behind Clark she walks over to it and turns around to face Clark, which puts the painting behind her even though it was already behind her before she moved.