Replacements - S1-E4
Other mistake: When Heffron is taking his throw at darts, he states that he needs a "double seven". When he takes the throw, the dart goes into the treble eight (an earlier close-up confirms that the board has the standard Gamlin configuration), yet, from the reaction he gets, he's made the throw he was going for. (00:04:40)
Other mistake: During the scene when the soldier who shot Sergeant Grant on the head was captured, Captain Speirs with a drawn M1911 pistol (hammer not cocked) is seen entering the building. In the interrogation room, it appeared that Capt. Speirs pulled back the slide of his pistol (this is after hitting the face of the captured soldier with his pistol). Speirs then aimed to shoot the captured soldier's head. Sergeant Perconte slowly stepped back (fearing he might be in the line of fire). Clearly it can be seen that the hammer is still not cocked. Then a sound of what appears to be a clicking (or unclicking) of the pistol's safety by Speirs.
Answer: He bit off a piece of a cigar.