Factual error: A recurring mechanism in the series is if the power fails the prison cells that are magnetically locked open immediately. No magnetic locks are designed like this. They would fail their initial purpose which is to provide physical security. If a power outage occurs it would take hours before the locks would be released.
Continuity mistake: In the series finale "Chuck versus the Good-Bye", Chuck and Sarah are in the Wienerlicious waiting for Quin to show up, Sarah begins rearranging the cups. There are three stacks of cups, and after she has set the third stack down, the camera cuts and she is now just reaching for the third stack. (She moved the third stack twice.)