The only time I've made a surrender work was when I barrel tagged a vet in the back, it's never worked any other time so I don't bother with it. I just aim for the pod pack if I have a backshot.
I also don't think you can really surrender a room full of people either. If you have the skills to go all Delta Force on them as you claim then just do it, have fun servin your pie, and sort out the 'should of, could of's' later.
The end result wouldn't be your fault. People who camp in buildings need to accept the fact that they have chosen to be in a place were their elimination will probably take place at very close range, and probably with some amount of pain.