I got this once on a library PC and a pop-up image of the most explicit porn.

I would suspect the hacking would be at the server for the streamed video. A trojan resident and if very well thought through would only superimpose occasionally. It would be harder to spot & find, because I doubt there is a numerous crew supervising, and probably not monitoring.

If the software is anything like we had at the radio station the programme files are scheduled and if there is an over-lap then the outgoing file is dropped immediately.

I have seen this on BT TV (UK phone provider cum TV channel) even the adverts are clipped, though this may be exacerbated by the crap broadband and the multiple time-delayed streams switching back to the newest one. Either way it reflects their amateurish results throughout. Probably one person per shift supervising 5 channels plus a load of other house-keeping.

It is all down to the money they throw at the task.

Personally I would not watch any Russian channel, a short viewing of "Russia Today" would show how biased it can be. Like Fox news you say? About the same.