And (unless I missed it) the local French article didn't even mention Billy and Gwen by name. It only referred to them as Chatelain/Chatelaine.
When the accident happened at la Lande several of us were looking for it in the French papers. I know I tried and it was so difficult because there were never any names of people. I remember scrolling through days of reports on a couple of local French newspapers, scanning for names, and none were ever there. Then, I had to read and look for the type of accident and where it occurred, because at the time, it was not known that it had happened right at la Lande. It was very difficult. If I remember correctly, someone here who lives in France said that's how French newspapers report news like this.
I've always thought of the Daily Mail as a total rag of a paper. It could be possible news reports in France were picked up by a news service via Daily Mail, since where the Pethericks live has a lot of British expats with readers in the UK would be interested in. Then, when the Daily Mail saw it, they put two and two together and knew it was the Pethericks? Or they had a source at that courthouse who confirmed it was the Pethericks?