Counter-point for PBP
If a guy who I don't consider a physical threat, and who should know he doesn't stand a chance in a fistfight with me, decides to break in my door...
... I will probably assume he's brought a weapon. Otherwise, he'd just be stupid.
I agree the firefighter shouldn't have left provoking messages, and that he should have involved the police a bit sooner. However, I think it reasonable for him to have thought the decedent likely to be armed at the time of the break-in, based on behavior.
Granted, it's possible the decedent used a key, instead of kicking in the door, but it does say that the ex-girlfriend called the police when she heard the pounding on the door. It seems illogical that somebody who had a key would pound on a door more than once, before using the key. My inference would be that he broke it in, but maybe we'll get more facts reported at a later time.
Criminally, this should be "not guilty." The civil suit could be another matter.
Just my $.02.