I think I have an idea.
You're about to do a spy swap right at the border. It's nighttime.
Bright spotlights are lighting up the area, which means you can see
clearly the space you're in, but everything else is totally black.
Everyone is as suspicious as hell, and on the lookout for a double-cross
of some kind. Both sides are armed to the teeth. Presumably there are
snipers all around beyond the edge of the light (we know about at least
one!).
You start walking forward with your guy; they start walking forward with
Laura. When you get about 25 yards apart a shot rings out. *Nobody but
you is expecting this.*
First, it's a wonder it didn't start a fusillade!
Everyone runs pell-mell in the direction they consider safe. Laura drops
-- she's literally dead weight, and her guards are more worried about
saving their own skins. East Germans run east, British run west. The
British have to hold on to their guy, or he might run *east* -- the
direction he wants to go anyway.
What do you think is going to happen to a British agent who runs east at
that point? He could have a gun, a grenade, anything. I think he would
be mown down before he took two steps.
I think that's why Neil didn't try to drag her back.