When I was very young, we lived in an apartment setting, and we there were plenty of other children to play with.
We weren't rich by any stretch of imagination and with me being the youngest I always go both hand-me-down
clothing and "looked after" by the 3 older kids (brothers and sister).
Anyway, the knock and run game was something that the older friends would do, and my older brother was always
loath to bring me along but there was no one to watch me while he went out playing the game. (He'd complain that
I was a slow runner, anyway).
So, one summer night after playing many outdoor games, someone suggests that we all go play the Knock and Run
thing. I'm a little game for it because I want to be "in" with the older kids, but I'm a bit leery because all day I've been
having issues with my hand-me-down shorts... the waist of my oldest brother was much larger than my waist, and the
darn things have been falling down around my ankles for the whole day... but I don't say anything, of course.
So, now we're playing and finally I go to run, because man-o, that lady opened the door really quickly, like she was
waiting for us! And the other kids are all running flat-out like Satan himself was after us. But me... well, I'm dealing with
my pants issue. And I run, and they fall down... to the ankles... I pull 'em up and run... and they fall down. I can hear her
getting really close and I start panicking and struggling to run and dealing with pants and she's getting closer.
But then it seems like I'm getting away... she's further and further behind... and I'm still struggling. And I hear laughing.

Well, at least I didn't get shot... in a very unflattering place to get shot.
All in all, the man/shooter in the OP was most likely an a-hole at best... but as was pointed out, I don't think that we got
the whole story.
IDK...