Hi Mike....i had this happen last year,looks like a carbon copy of the suite i cleaned.
I wasted a lot of time trying to remedy it and came to the same conclusion as you, that it had been washed previously.
I did find out from the manufacturer of the suite that the fabric was discontinued (that tells a story) but to cut a long story short i handed it over to my insurance company to deal with explaining what i had used (fab restorer and ultimate) and they actually came down on my side and dealt with the problem for me.
As far as i'm aware the customer either gave up or went back to the manufacturer for recompense as i never heard anymore.
This has been quite common recently,a cc friend of mine had an extract from ncca magazine which he promised to show me about this problem but we've yet to meet up,at the end of the day you've just been unlucky as i cleaned an almost identical sofa on the same job ,different fabric but you could hardly see a difference between the two,same products ,and no problem.
Even if you pretest which i did you can't predict this horrible result.
I think Mike Halliday had a similar experience around the same time as me ,whether he managed to put his right i don't know.
Hope you get it sorted but my advice would be to let your insurance deal with it and let them take the stress.
Cheers
Matt