A fascinating upload courtesy of the always interesting VHiStory blog...
As mentioned (by me) on here a few times, it's the apology after the Smack The Pony episode with a sketch suggesting "a small explosive device would f*** it up nicely" went out on the night of the Soho nail bomb. The apology really is a terrible bit of arse-covering by Channel Four, because it it was, as they say, "too late to edit it out", they would have dropped it completely and shown something else. They clearly just completely forgot it was in there.
As has also been mentioned here, that same night BBC1 showed an episode of Only Fools and Horses where they went to a gay bar, and got loads of complaints it was inappropriate.
The whole story, and some lovely grabs of brilliant Smack The Pony sketches, is at
https://vhistory.wordpress.com/2020/02/18/smack-the-pony-the-simpsons-king-of-the-hill-tape-2603/