Dogpile sent someone here searching for “shoot or wait for 911.”
If the function of the police were to protect the citizens, it might make sense to “retreat as far as possible and wait on an emergency response.” But the function of the police is to investigate a crime and make arrests, not protect anyone other than the politicians who pay them.
In many cases, waiting means you might see someone tomorrow. Or not, if the response drives by your house, sees nothing, and does not investigate. Even under the best of circumstances, a 911 response often takes longer than the crime. As this Denver 911 call demonstrates:
So the logical response is to shoot if you have to, in order to prevent injury to yourself or to a family member.