Well it certainly makes me feel a little better that everyone is experiencing these bugs with the Oathbreaker quests, not just me.
It has to be something to do with the way video files are being handled, right? I'd guess it was meant to be a fix to the persistent issue of the splash screen animation making the game lock up on startup, and it managed to both break other animations elsewhere and not actually fix the issue at hand.
Shit sucks, but people here are way too mean to devs. Maybe some of them are just greedy or lazy or whatever, but I have to imagine that Naughty Underworld is mortified right now at the realization they managed to break a part of their game that was working before. This is just the price one pays when playing prerelease games, y'know?