While Lex and Phelan are talking in the Beanery, the score on the pinball machine behind Phelan changes from 9,000 to 3,000 to 14,000 over the course of their conversation.
When Phelan first begins talking to Lex in the Beanery he is standing facing Lex, hands empty. When the shot cuts to Lex and back, Phelan is suddenly holding a coffee mug and is partway through swallowing.
When Clark enters the Torch office to talk to Lana, he doesn't have a coat. As he leaves, he is holding one in his hands.
When Clark visits his father, after Jonathan has been arrested, Jonathan is clearly not at the police station but is already in jail, as the orange jump suit indicates, yet it is only a few hours after his arrest. In reality he would still be being questioned by police, or in a police cell while awaiting the arrival of his attorney.
The driver of the city bus appears to be having a heart attack when he loses control of the vehicle. After the crash he gets up, relatively unharmed, despite the apparent heart attack & being in the exact part of the bus that sustained the most damage.
Phelan fires the gun at Clark and Clark evades the bullet in a slow-motion shot. But then he looks through a milk glass window and sees the shadow of a person walking in normal speed which then makes him change directions while being in slow-motion.
Just after Jonathan has been arrested, Clark walks into the house and punches a wooden beam. If you look closely, you can see the crack in it where it has already been broken.
Whenever Clark pulls the chain taut to suspend the engine in the barn, he hooks the chain to a beam in the barn. You can see the chain wobbling in the next shot which shows it is not attached to the engine because it would be taut with zero wobble.
When Phelan and Clark drive away from the farm, for a brief moment you can see a shadowed outline of a crew member running by the house before ducking down by the fence to get out of the shot.