Other mistake: In Shepard's apartment, there is a fresh pineapple and other fruit in his kitchen. This despite him having been in Atlantis for several months. This later turns out to be an artificial reality, but that should've been a big hint.
Captain Defenestrator
2nd Mar 2021
Stargate: Atlantis (2004)
9th Nov 2013
Stargate: Atlantis (2004)
Quarantine - S4-E13
Revealing mistake: When Dr. Zelenka drops into the room from the ceiling vent, the wall with the monitor projecting the map of Atlantis vibrates as he hits the floor. (00:38:00)