Visible crew/equipment: After Clark and Lex get out of the tunnels, and the explosions follow them out, we see Lana and Chloe arrive in a dark car. When they get out of the car, the cameraman can be seen reflected in the door. (Time)

Factual error: Lana is trying to find out what Lex is up to. She gets a hold of his briefcase and takes it to the mansion where she shoots the locks off the case. When she does the case jumps a little bit but this is far less than it should. She is shooting at it from less than a foot away. The force of the bullet should have sent that case sliding across the desk at that range. (Time)

Plot hole: Clark is crippled throughout much of the episode due to their being kryptonite in the tunnels. At one point he gets a rock stuck in his arm and he bleeds from this wound. For much of the time after this he has blood running down his arm from this wound. After he gets out of the tunnel he is healed but the problem is the blood from the wound also disappears. The actual wound should have healed up but the blood from that wound should still be shown staining his arm.

Factual error: Lana opens Lex's briefcase with two shots from a semi-automatic pistol at point-blank range, yet the glass table underneath the briefcase is completely undamaged. Submitted by wizard_of_gore