Continuity mistake: When Clark blows out the barn doors, they go out at a fairly low angle to the ground. But when they come down next to Lois they drop down straight out of the sky.
Suggested correction: The pieces of the barn and door blown off are on screen for a second or less and don't travel far enough on screen for you to predict their trajectory. They could have easily been moving upwards without being able to tell. The barn door travelled far enough that it would have risen higher into the air.
Continuity mistake: When Lana was making a video to send to Whitney, we see her interviewing Clark. We first see Clark through the camera's view finder. Lana then drops the camera (pointing it down) such that we see Clark's feet. Cut to a different angle but now Lana's is pointing the camera at Clark's chest level.
Continuity mistake: Gabe Sullivan's headstone is on the right side (if you are looking at the headstones) of Chloe's in the previous episode. In this one it's on the other side.
Vortex (2) - S2-E1
Continuity mistake: Nixon raises the bar to kill Jonathan with a ridged side up, but when he is shot he is holding the smooth side up. (00:32:00)
Continuity mistake: When the Phantom child kills the doctor and drags him over to the fingerprint scanner to open the door, we see the doctor has no glove on his hand when it is placed on the scanner. But when his arm drops to the floor, there is a glove on his hand now. (02:32:35)
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: At the start of the final race there is a bridge at the far end of the road that Pete and Jason are going to race to. During the entire race they never pass this bridge yet it ends up behind Jason's car when Pete looks in his rearview mirror as the crash is going on.
Audio problem: After Ryan collapses at Lex's, he and Clark are talking while Ryan is in the hospital. In the shot of Clark as Ryan says "I know what's wrong with me." Ryan's mouth is visible and you can see that he is not speaking the line as we hear it.
Visible crew/equipment: As Clark is ambushed inside Belle Reve, in shots focusing on Lex as he is being beaten by the twin and again a few seconds later, there is a dark object in the upper right corner of the shot. There is nothing in this scene to explain it and it moves with the camera so it is probably some piece of filming equipment. Regardless of what it is, it should not be in the shot.
Continuity mistake: When Clark is in hospital after being thrown to land on the roof of the car his mum is helping him put a shirt on. He puts it over his right shoulder and the shot changes, his arm is all of a sudden in the sleeve.
Continuity mistake: Clark had been wearing his cap and gown for a while. When he takes them off while coming off stage the blue shirt he has on underneath has fresh raindrops on it like he had only put the cap and gown on a few minutes before the shot.
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.
Audio problem: Sean drops frozen Jenna and she shatters. He then manages to casually walk out of the room over her without crunching any of the ice. (00:17:30)
Continuity mistake: At the Daily Planet, after the opening credits, Clark tells Chloe that he found his mom unconscious in a field. He did not find her in a field, he found her in the driveway in front of the house. Later, at the hospital, Clark tells his father that he found her in the driveway.