It’s actually not that hard to mess up someone’s life with a little bit of subtle, uncomplicated hacking.
The scariest part here is how the victim’s friends and family all assumed he was delusional, to the point of sending him to a psychologist. Ironically, this very thing was a plot point in the game Phantasmagoria 2, way back in 1996. Except in that game the “hacker” turns out to be… well, spoilers. But not a noob with a Kali CD, shall we say.
Technology marches on.