Ummm what?
When I see on the top right a bunch of zombie kills, my first instinct is that the zombie is both a speed and coming close to the doors. So if I see a group of guys coming I am quick to close the door when I know they can all make it safely. Can't always get everyone through.
I didn't close the second door before it had to, and I didn't block or get myself tagged through the boxes. What are you talking about.