Thanks!
I have been searching the image, and I think I found it:
2010-ish Scott Speedster 50 with flat handlebars
That does indeed claim the fork is "carbon/alloy", which explains the previous owner's confusion.
But a review in Cycling Weekly says "The first disappointment to mention is the alloy fork, which gives a harsh ride and passes every bit of road buzz on to the rider." (https://www.cyclingweekly.com/reviews/road-bikes/scott-speedster-50)
I smell "marketing dept. carbon-fiber" :) If anybody knows where a "carbon/alloy" fork may have used carbon (I can't find a spot that doesn't -ding-), then I'd have some idea how it might fail carrying panniers.