Most of the people who’d believe a video saying the opposite of what they’d expect is real have never been aware of deep fakes.
And now thanks to this poor deepfake they are aware of deepfakes and are primed to question future videos, even if they seem real.
Videos being fake? That's asking an order of magnitude more scepticism from them.
They may also be primed to question real videos. Aka “flood the zone with shit”.
Years ago I read somewhere that the way Russia does cyberwarfare is less organized than most people suspect. I'm not sure if it's true, but the argument is that it's more of a lousy goosy free agent type deal. Some of these agents are very clever, but others not so much, so you have a range of competencies just trying stuff.
That could be wrong, or they may have evolved a lot since, but amateurish deep fakes could be a fit. Some random kid just trying stuff and hoping for a pay day / bounty? Pure speculation though.
I had the feeling Russia hasn't used their best men and equipment yet, which also seem less likely bu the day