Revealing mistake: As Krypto presses the button to open Hercules' cage you can hear the button beep as if it has been pressed but the green light is still on. Earlier the beep which means the button worked also turns off the green light.
Revealing mistake: As Clark is chasing after the semi-truck with Lois and Lucy in the trailer you can see the Rocky Mountains in the background. Kansas doesn't have mountains. However, Vancouver, where the show is actually shot is home to part of the Canadian Rockies.
Revealing mistake: After everything with Dawn is over Clark goes back to the prom. Clark asks Lois if she wants to dance. Lois says "I'm not the one you want to dance with." and she nods to the door. The shot switches to show Lana walking in to the prom. When Lois makes her nod to the door Lana would have been completely out of sight. Lois nods before Lana even enters the room.
Suggested correction: We never see Lana walking into the gym. She's just standing at the door, nervous about going in. We don't know how long she was standing there. Not to mention the fact that the scene of Lana at the door could have happened at the time Lois was making her comment and Lana walked in before the first time we see Lois look at the door, before she nods.
Revealing mistake: As the helicopter that Lana is in dodges the falling meteors in mid-air, the camera shot focuses in on the cockpit. If you watch Lana's position as she first starts to appear she is semi-transparent and the frame of the window behind her is visible through her body.
Revealing mistake: After Lana is warned by Chloe that Clark has gone all 'Captain Paranoid', she examines the silver 'meteor rock' more closely. We see a shot of her hand holding the 'meteor rock' but the hand that is shown is obviously not Kristin Kreuk's hand.
Revealing mistake: At the beginning, 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.
Revealing mistake: When Clark has the Kryptonite and uses it against Zor-El in the fortress, Zor-El climbs upon a flat surface or hard ice for support. As he gets onto the surface, it shakes like a soft prop. (00:30:20)
