Rillington Place : The families of Evans, Christie, Beryl, Ethel and the other victims

Did they have anything to say about the series?

No idea, but Evans's family have reason to feel particularly aggrieved as they've turned him into an Englishman. Unbelievable.

I thought the same but apparently he used to talk cockney when in london to blend in and slip back into Welsh with family.

Politicians are like Nappies. They should both be changed frequently
and for the same reason."

It was his half-sister who let the producers know that he adopted a Cockney accent when talking to Londoners and reverted to the Welsh accent when speaking to Welsh friends and family.

Or, to put it another way, "My mind is made up, don't confuse me with facts". It's you who's unbelievable.