The gunman from the beginning said he wanted to surrender even though he held us at gunpoint.
He asked for the handcuffs to be thrown into the store so he could handcuff himself and walk out.
As it turned out, he cuffed himself and had the hostages walk close to him as he came out so the police would not shoot.
It was very much like when the police tank pulled up, he had us all sit together, touching so that if the police shot from the tank it would insure us as well as him,.
Well, there you go (if I understand your post). There was no reason to shoot at that time, given that he handcuffed himself and surrounded himself to prevent being shot. So, the police shot anyhow, killing a hostage. Nothing will happen.