At the end of the chapter, when Lana was talking to Lex about his experience with death she had no earrings, in the next shot, one earring appeared in her left ear, then it disappeared again.
When Lana swipes into the medical lab, the magnetic strip is clearly facing the wrong way to be read by the lock.
You can see Clark's breath when he arrives in Honduras, a country where the average low is in the mid 60s, obviously an indication that the footage was shot in a much colder climate locally in Vancouver.