Incomplete Anecdote Alert!

In my previous post I wanted to insert a reference to an old anecdote. Upon seeing a certain move, a certain grandmaster states, "I'd rather resign than play such a move!" This anecdote was to be referenced in this line:

Pace , I can imagine certain players would rather resign the game than play such a move!

Only I forgot to put in the grandmaster's name after "pace". Whoops.

There was a reason for that, though. I couldn't quite remember which grandmaster had said in in relation to which move. (I'm sure it's been said many times by many players, but I've got a certain example in mind. It's somewhere in my books, but I can't remember which one. GRRR.

I thought it was a comment by Pachman concerning a move in the game Portish-Kavalek, Wijk aan Zee 1975, but that doesn't appear to be the case. Maybe it was Bent Larsen discussing the Breyer Variation of the Ruy Lopez? No, that isn't it either. And now I've got no idea.

It sounds like an anecdote that Kavalek would have told, so maybe it's somewhere else in the tournament book for the 1975 Wijk aan Zee tournament. Or perhaps it is in one of Speelman's books? I've got no idea. It also has the vague ring of either Korchnoi or Botvinnik about it. A web search hasn't helped. This is going to drive me nuts until I remember it.

UPDATE: In the comments Paul Leggett supplies the answer! More detail (excruciating detail) can be found here.