Oh god, that sounds so familiar!
Is it one of his Tales of the Unexpected? (Sorry, I know that's a really obvious answer but I can't think off the top of my head of any others...)
(Sivvus trolley collision in the fruit aisle led to a jam, Sat 5 May 2012, 23:48, 1 reply)

I've never been able to find it again, so I can't confirm!
I believe it was in a special anthology for subscribers, multiple authors, one of those big books that is sent as a gift-with-subscription, and people keep in their libraries to look educated. So unlikely to be in a bookstore or even listed as a usual publication.

But if I recall correctly, it was a Dahl and so characteristic of his short stories!
( kila is reading clocks upside-down as usual, Mon 7 May 2012, 8:44, closed)

Any of these?
en.wikipedia.org/wiki/List_of_Roald_Dahl_short_stories
(Sivvus trolley collision in the fruit aisle led to a jam, Mon 7 May 2012, 20:25, closed)

Not on the list. Perhaps I'll realise I've hallucinated the whole thing.
Or it was another author. *sigh*
Dahl wrote the short story about the nervous wife whose husband got stuck in their elevator, didn't he?

I'm going to be searching for this one for ages!
( kila is reading clocks upside-down as usual, Tue 8 May 2012, 9:30, closed)