Forgetting you were there: bad
Assessing the situation before deciding to use the weapon: good
As a personal handgun owner and as someone who was trained and certified for years in the state of Texas for carrying, I can tell you it is not normal nor healthy behavior to draw your firearm and point it at someone in this situation. You don't just "forget" that you have or have had guests in your home, and you don't point a gun at someone unless you are prepared to use it to kill.
If you want the responsbility of owning a handgun, it is doubly your responsibility to be
Eveni n the bizarre situation that he forgot he had a guest over, it is incredibly irresponsible and a little deranged for his knee-jerk reaction to be to point a gun at someone without assessing the situation first. Speaks highly of PTSD, and no citizen should own a gun if that is their first response to ambiguous situations.
Rough neighbourhood??
Red Flag? Really. What should he do. When he comes upon an armed intruder he should ask them to either A wait patiently while he goes and gets his firearm or B: Hope they don't shoot before he can pull it out of it's holster. Also, the PTSD comment makes it seem as if anyone that has PTSD shouldn't be allowed to have firearms because the boyfriend and anyone else that has it is just too emotionally unstable. That is extremely far from any truth or facts.
Is your boyfriend Oscar Pistorius?
Forgetting you were there: bad
Assessing the situation before deciding to use the weapon: good