Continuity mistake: When Glenn is with Tara and getting ready to move out, he puts on his helmet and you can see it is strapped on. When the shot changes, he swings the fence open and you can see his strap is lose. The camera angle changes again and the strap is back on again. (00:38:15)
Continuity mistake: When Glenn wakes up we see the door behind him is flush with the concrete, but when he goes inside you see stairs he had to descend to get to the door. There is also no scene in the entire prison episodes where an outer orange door is preceded by steps, they are all flush. Also If you look at the door behind him you see two folding chairs leaning up against the door. When he turns to open the door the chairs are gone.