They left the door locked?

If you watch the scene where Koskov "defects", he escapes the building and runs across the street while James covers him from the KGB sniper. At this point James believes that he is actually defecting and also believes that the enemy sniper is a real sniper trying to take Koskov out.

But when Koskov arrives at the door he has to wait outside for a decent amount of time while James and his spotter come downstairs to unlock the door and let him in. What if James had missed or there had been two snipers? Koskov would have been a sitting duck out there while he waited to get in.

Not that big of an issue, but it gives me a laugh when I watch that scene.

There's much bigger questions than that in the movie. Why is it that MI6 agents would search a milkman to see if he had any weapons on his person, but they don't bother to search the truck at all, and then let him get back into the truck, and let him drive into the place?