The vehicle transmitted MPEG4 video, that then had byte level corruption due to transmission issues. MPEG4 really doesn't like corruption.
Or is the transmission streaming, or is the receiver re-encoding it?
> how can you have a current in a single wire without a loop?
There are ions always wandering around in the ionosphere - the ionosphere is partly-ionized plasma. Low-density, but there. When you have a generator that produces an electric potential bias across the top/bottom of the craft, you end up with electrons being emitted into space from and positive ions being attracted to the side biased negative, and electrons in the ionosphere being attracted to the side biased positive. Effectively: the plasma completes the circuit. There are bunches of additional optimizations (electron guns, etc) but that's the basic idea.
Also how could such a generator work? That makes a potential on the two ends?
For example, one of the major considerations for how the ISS orients its solar panels is minimizing drag.
And that's what an electrical generator does. It produces an electric potential difference between its two terminals.
More accurate to say that it was messing up the decoding of following blocks.