Continuity mistake: When the weather vane falls to the ground the rooster portion of the vane gets bent. When Jonathan picks it up and starts to angrily walk away from Martha and Clark it is straightened.
Visible crew/equipment: When Prof. Joseph Willowbrook and Lionel Luther walk down the steps of a building, talking about the possible whereabouts of Jeremiah Holdsclaw, they begin to cross the courtyard, which is bathed in sunlight. As they walk across, and eventually walk under another building, as they cross the courtyard, you can see the shadow of a large reflector board moving along with them as they walk.
Continuity mistake: At the end of the episode, the doctor takes the mouthpiece out of Lex's mouth, then the scene cuts to Clark. When it cuts back to Lex, the mouthpiece is back in his mouth.
Revealing mistake: At the beginning of this episode Lana is supposedly naked. However, when she dives off of the pier, she is wearing a pair of red shorts.
Continuity mistake: After Clark gets his powers back the cut on his cheek heals and leaves only blood on his cheek. While still at the power generator he goes to wipe this blood off of his face with the back of his hand only in the shot just before you see his hand go to wipe, a second before his hand actually appears on screen, the blood that was on his cheek is now gone as if it was already cleaned.
Continuity mistake: As Lana starts her second swing at Chloe with the axe while the camera is in front of Lana Chloe is just barely getting up and is still close to the floor. The camera switches in mid-swing and suddenly Chloe is completely standing and is able to jump back to dodge the swing.
Other mistake: When Clark confronts Jason Dante and tells him the race is off, one of Dante's thug friends picks up the krptonite/nitrous oxide booster tank and only then does Clark start feeling the effects of the kryptonite. Even though the tank had been sitting out uncovered well before the guy picked it up.
Continuity mistake: When Seth is testing his powers in the hospital room he tries to move a cart at the foot of his bed. To do this he has to raise his hand to use the magnetic power he has. In shots from the front his right hand is palm down using his power but when the shot switches to behind Seth, to show the cart starting to move, his palm is now turned towards his left. His hand is back to being palm down when the shot switches back to the front.
Continuity mistake: When Lex tells Clark about Lionel finding the wire, Clark moves over to Lex and says that finding something incriminating on Lionel shouldn't be too difficult. Between shots, Lex and Clark's positions change in relation to each other.
Phoenix (2) - S3-E2
Continuity mistake: When Lex pulls the gun on Linoel, when the camera is on Lex he is pointing the gun in Lionel's face. When the camera is on Lionel, Lex is pointing the gun in Lionel's chest.
Continuity mistake: When Clark goes to give the flowers to Sarah, her uncle answers the door. The first shot is of the uncle through a flyscreen door, which he opens. We then see a shot of Clark outside the door, and then the uncle opens the flyscreen door a second time.
Continuity mistake: When Lana undresses before jumping into the lake, she kicks all her clothes right beside Clark's feet. But in the shot where she dives off the end of the pier, all of the clothes are piled well away from Clark.
Continuity mistake: During the flashback that happens at the Luthor mansion, the one that starts with the cup shattering on the floor, young Lex is shown peeking through a slightly cracked open door. Just after Lionel asks the nanny to give him Julian there is a shot of Lex peeking in and you can see that he has hair on his forehead. Now Lex, at this point, would have been bald, as a result of the meteor shower in Smallville for several years and would have no hair at all on his head in this flashback. In fact when Lionel finally realizes that Lex is outside the door we see that Lex has no hair on his head.
Suggested correction: Lex is bald but still has eyebrows. There's never a shot of young Lex with hair on his head. You never even see his head when he's peeking, but you do see the hair from his eyebrows.
Audio problem: Towards the end of Lex telling Clark about his car, that it was stolen and returned, Lex says "Often that can be the test of a true friendship." After Lex's line the camera switches to show a reaction shot of Clark. In that shot, just before it switches back to Lex, you see Lex's mouth move as if he is saying something but there are no words heard.
Revealing mistake: Loder gets scared and tries to get away from Kara. He takes off down the road at a significant rate of speed. Kara uses her super speed to get in front of the car. Loder has to slam on his brakes to keep from hitting her. At the speed Loder was going at he should have either skidded to a stop or hit Kara with his car. Loder is able to stop his car without doing either.
Continuity mistake: As Lana is walking up the stairs to Clark's barn loft, from the front shot Clark has his hands to his side. When the camera jumps to behind Clark, watching Lana ascend the stairs as she says "I, uh, came by to say thank you." now Clark's right hand is behind his back and not to his side.
Continuity mistake: Martha is putting together a flower arrangement. When Jonathan is talking about Clark not eating the last piece of cherry pie, in a shot of Martha and Jonathan, Martha is picking up a branch of white flowers and holding it in front of her. When the shot switches to Clark, you can see her putting this same branch of white flowers in the vase even though she made no motion to do so in the previous shot. This is supposed to be continuous since you can hear Jonathan talking between the shots.
Continuity mistake: As Clark stands outside the room where Lex has just got his shock treatment the blood on his cheek is back even though his cheek wound was healed and he wiped any residual blood off in the previous scene at the power generator.
Continuity mistake: Just before Clark gets the call from Lana we see inside the trunk of Pete's car. At this point there is a coiled rope in the trunk turned parallel to the rear of the car. When Pete gets the rope for Clark a little later the rope is turned perpendicular to the rear of the car.
Plot hole: When Kara realizes that Agent Loder is listening in on the conversation, she runs out to his car to stop him. She has Clark's ability of super speed which she uses to get over to Loder's car. As she runs she ends up running through a wooden fence and you can see, through the motion blur of her movement, she neither jumps over the fence or goes around it yet the fence never gets damaged from her running through it.