Continuity mistake: As Lionel's cellmate tells Lionel "I've always kind of had a thing for pattern recognition." the shot changes mid-sentence. Between changes Lionel's cellmate goes from having his arms crossed, hands holding his elbows, to having his hands almost clasped together.
Continuity mistake: Martha visits Lionel in prison not knowing Lionel is actually Clark. As she says "I'm only here because you told me it had to do with the safety of my son." the camera changes. Between changes, as Martha says "you", her left hand goes from being under the table to instantly being on top of the table.