It seems to apply here. I would stipulate that this appears to meet every condition I would have for a legal, appropriate defensive shooting.
From the Philly PA NBC news by way of MSNBC.com:
Pistol Packin' Mama Kills Son's Robber: Cops
A Philadelphia man was shot dead Tuesday night after he made the mistake of trying to rob a man who had a pistol packin’ mama nearby, police say.A 23-year-old man was in the stairwell of his East Oak Lane apartment building with his girlfriend at about 9 p.m. when a 19-year-old man walked up to them, pistol-whipped the man and shot him in the leg while trying to rob him, according to police.
The victim’s 46-year-old mother heard the commotion from her upstairs apartment, grabbed her legally registered gun, went into the stairwell and shot the suspect, police say.
The 19-year-old robbery suspect died at the scene with one gunshot wound to the chest, according to authorities.
The 23-year-old man was taken to Einstein Medical Center where he was in stable condition Tuesday night.
“Upon police arrival, [the woman] gave police her weapon and she told us she was intervening in a robbery and she was protecting her son,” Philadelphia Chief Inspector Scott Small tells NBC Philadelphia.
The 46-year-old mother has not been arrested, but she is being interviewed, police say.