'You've been a bad girl' isn't a term an very angry male would use.
IYKWIM. In this case it sounds um bondage/strange?
I think I may have posted about this before.. sorry if I'm repeating myself. But this really struck me.. I used to work in the BDSM industry (though it isn't at all "my thing", heh) and I got to hear a LOT of both roleplaying and full on devotee talk. And I've also studied the dialogue of power assertion rapists. And those words are, in *that* situation, what Id fully expect to hear from a man who's crossed a line between a fantasy script he's been running in his head and what's really happening.
You can see it evolving through the whole tape, how he manipulates and exerts power, of coersion, of bullying, of threat, taking her phone.... and you can see through the whole tape how he kept focussing Rrie on the balcony, it comes up over and over...
I have NO doubt that the idea of using his balcony as a threat and a tool of total power exertion was turning him on. "You've been a bad girl" is both infantalising her and exerting dominance, power. It's mockery, of someone he's got scared witless. It has, to my mind, and keeping in mind I *know* the fantasy talk/mindset of sadists/masochists pretty well -- the tone of someone sadistically enjoying another person's fear and the thrill of the sense of power it brings.
This doesn't mean I think he's into BDSM (though he might be, he did have her tied up at one stage...). But I *do* think he'd been harbouring some pretty sick fantasies for quite some time. And I say "sick" because I don't think they involved willing partners.