Continuity mistake: Quinn is clean shaven when sitting by the pool with his girlfriend. The action shifts to Carrie in Pakistan and then back to DC where Dar confronts Quinn in the motel. Quinn now has a mustache and a bit of goatee, which he has for the balance of the episode. While the precise timeline is unclear, everything is fast paced and it seems that virtually no time has elapsed, certainly not enough time for Quinn to have grown a mustache.
Continuity mistake: As the young girl is in the kitchen cooking and goes to answer the door she puts her sari on. When she answers the door it's no longer on her head and is around her neck. When she closes the door she then has the sari back on. (00:05:10)
Continuity mistake: When Lt Col Khan leans forward in the airport scene his epaulette can be seen to bear only the single pip of a second lieutenant. When he stands up again he is wearing the pip and emblem of a lieutenant-colonel once more.
Chosen answer: Everyone else calls him Brody or Sgt. Brody, and it probably became habit to her.
The_Iceman
Can't get the source but I read that even the Producer responded to that. Stating that it was common practise for a military wife living in a military complex as everybody refers to their husband by their last name.