Bumping this thread, just had a text from ClaimJet with a link to a website travelwiseway dot com slash uk.
I'm guessing this was because I was on the BA085 on the 23rd December which indeed arrived four hours late. Some of this was due to the inbound being late, some of it due to an engineering issue whilst boarding, and some of it due to a medical emergency necessitating return to the gate.
However I don't know how they got my data.