it might be possible. i know of a dude that was killed 6-7 years later over a grudge from 9th grade. You right, the stories on this could be exaggerated or fabricated, The story of the dude from my city that got killed, apparently when he was in 9th grade he beefed with a kid briefly. if you can even call it a beef, i think they fought or something and the other kid dropped out or got expelled, they were both suspended but anyway dude from my city came back to school, graduated 3 years later......is living life and is now 21-22 in a club. He's drinkin with some cats, maybe smokin too. Club closes and as everyone's leaving another dude starts buckin shots kills the dude.
Now the news stories at first were calling it a gang shooting, turns out nobody had gang ties. People who were there were saying it was his friend who was shooting at someone else and accidentally hit his boy (which didn't really make sense but since he was drinkin with this fool and there was no argument i guess people assumed they were friends), They caught the shooter and pulled his record and he's on file for fightin the dude like 6-7 years prior
its either maybe the dude snaked him and was acting like they squashed the beef on some 'we were kids' shyt then came back blasting or the dude really didnt remember him.