Continuity mistake: After signing the non-disclosure agreement, Caleb drops the pen on the right of the pad on the desk. In the next shot the pen is almost in the center of the pad. (00:10:10)
Continuity mistake: The last power outage resulted in all the facility's doors being locked open. But in the final scene, Caleb gets locked inside.
Chosen answer: He inserted his own card in Nathans computer. Also, there was no mention of a power failure, only a red glow. This would be a different event than he's programmed the system for.