The context of the following conversation is Quinn was in a hurry to get to work and forgot if he had locked the door so he had to go back to double check.:
Quinn says I wonder if I locked the door to the house?.
The friend responds What's that Quinn?.
Quinn responds Oh, just thinking out loud. I may have left my house unlocked..
The friend responds There's a lot of crime in this neighbourhood. You have to go back and make sure or else find all your stuff gone..
Quinn responds Are you sure?.
The friend responds Yes I'll cover for you if anyone asks..