Phone scam goes off the rails

I got a call from a scam operator pretending to be from Microsoft support, calling because "lots of customers have been getting error with their computer". Sometimes I play along with these, because I think it's funny when they talk me, a software engineer, through extremely simple actions and try to get me to install spyware as if I am some clueless luddite. She directed me through looking at system event logs, and when I told her there were no errors, she put me onto her "supervisor". This is where things got weird.

He asked what I saw on the screen, then, when I couldn't understand some words he was mispronouncing, immediately launched into some sexually explicit threats. He was apparently unable to be deterred from this new train of thought and back onto tech support. I tried. I didn't take the threats seriously, because he didn't even know my name, let alone where I lived. He wasn't even in the same country, so "I'm coming there at 12" hardly meant anything real, but they still rattled me. I wasn't expecting them. Eventually he hung up.

What I can't understand most of all is the business logic behind this behaviour. I was playing along. I should have been a perfect mark, apparently ready to do anything they said, but before they could get me to install their malicious software, I got threatened and they hung up. Did they just get frustrated? Was the "supervisor" going rogue on his own, treating these calls as pranks because he was so bored? I can't blame him for getting bored at that job, but his threats were to a level that I would almost have called him demon-possessed.

The only explanation I can think of is that these two operators were starting to follow a script, but because they barely spoke English, they misinterpreted my inability to understand them as hostile, so they responded in kind. It's still bad business to waste time that way, though.

Mokalus of Borg

PS - Generally the best tactic in these situations is to put the phone down and walk away.
PPS - Don't hang up, though. Just leave the line active.