I don’t like to link to full episodes of shows that are commercially available, but have a look at this really odd moment from Citizen Smith.
https://youtu.be/rWLHozl8AFw?t=671
This is episode four of series three (Tofkin’s Revenge), which aired on 11th October, 1979. Now, I know that sometimes changes are made for the DVD, due to licencing reasons, and sometimes for taste reasons, so I don’t know if this is how the episode originally went out.
That pause and drop of audio could be a tape issue I suppose.
It looks to me like something has been excised, rather clumsily, with a laugh used to mask it.
Anyone have any more details about this?