Petula Clark lives in Geneva, Switzerland, and not France.
Her French is quite good actually, but with a very strong English accent. Strange considering she's been here so long and has obviously a good ear for music, which means she has a good ear for languages. Possibly part of her artistic persona.
Those who live in a new community and choose to communicate daily and totally with the locals, rather than expats (like so many Brits in France for instance, some who have lived there for 20+ years and still do not speak the language beyond a few basic words and sentences)- do unconsciously change their own accent, even in their mother-tongue. Not to impress or show-off, but because it just 'happens'. I know - as people here used to laugh because I sounded English in French when I visited after a few years in UK, and now I can hear that the reverse is happening (as I've been back for nearly 4 years now). My grand-son said it the other day when we were looking after them in Surrey 'Oh Granny, you sound all French today'. He found it hilarious, but not stupid, nor misguided.
. No problem.
The fact the guy is apparently stupid, and possibly misguided, is neither here nor there. Have a great week-end all.