Well, I came to make a thread about
this news article, but this thread is close enough to the topic.
Answered the door at 130 AM with gun in hand, shot dead by deputies who were at the wrong house and thought he was a murder suspect... Food for thought.
IMO, it's probably never a good idea to answer the door with a gun visible in your hand or in a threatening posture. If you think whoever is on the other side of the door is that great of a threat, why are you opening the door? Holstered or maybe behind your back, I can see.