From the HT:
P.S. Don't answer the door unless you know who it is!!!
Do you know the difference between a gun and a magic wand?
chefcook, i think your analysis is most likely. The intruder had to have come through the door in chase. this is why a long barrel shotgun doesnt make the best HD firearm. Ive instrcted my wife to never open the door for ANYONE if she is alone, unless she can identify the person from the 2nd floor hallway.
I think the problem would be this guy had no training. He bought a shotgun (maybe for this purpose maybe to hunt) but he never thought what happens when SHTF. When it did he froze. No one want to take another persons life (which is probably what happens when you use a 12g in a home) so this guy froze.
Its easy for all of us to say what we would have done (myself included) but with out proper training you are just as likely to freeze up. Although, most of us can not get real experience before something like this happens, you can get training.
i thought about this scenario, "how to answer the door"...and holding a shotgun whether in your hands or on a sling isnt a good idea IMO. showing your weapon will freak out an innocent knocker...while someone with nefarious intentions is going to be tipped off, which could lead to a scuffle and them taking your gun away.