But there has to be a sequel because quite simply the way it ends the Doctor loses and Earth is wiped out.
That's the way it is left as of the end of your first viewing of the episode. Then you go to bed that night and sleep normally. The next day, you know that the footage you saw must have had the infectious signal removed, leaving only the video glitches in its place. Somebody (probably the Doctor) got to it and fixed it. Maybe a future episode mentions how.
It's trying to be meta. Not that you actually believed you were infected in the first place, but I think that's the game it's playing.
I guess, but didn't the Doctor say the process had begun already inside Clara? If that is so would she have passed it on when the raven attacked her?