Toobworld has had problems with the onscreen credits for its characters in the past, where they're given names different from the way they're addressed within the show:
Ann Maxwell in credits
Ann Martin in show
CURB YOUR ENTHUSIASM
Dr. Salvin in credits
Dr. Slavin in show
Joshua Wheeler in credits
Joshua Donovan in show
Both Bradley James and Richard Wilson were listed as Arthur Pendragon in one episode. Richard Wilson played Gaius.
While on vacation, I found another in an episode of 'Foyle's War'. In "A Lesson In Murder", Joe Pierson - the 11 year old murder victim - and his father Eric Pierson (left) were listed as Coopers in the end credits, despite being clearly addressed and referred to as Pierson throughout the case.
As usual, what happens in the episode trumps anything listed in the credits.
And it's better for Toobworld to keep them as Piersons. They were from London's East End, and Joe had been sent packing to Hastings to avoid the bombings that had not yet begun. So it could be that Mr. Pierson and his wife either had another son sent elsewhere, or they had another child after the death of young Joe. And this Pierson offspring could probably be the father of the East End cardiologist who treated Roy Evans when he suffered a heart attack that led to his death on 'EastEnders'.
Sure, there are a couple of Coopers listed for 'EastEnders' as well, (especially Julie Cooper in 1989-90), but the chances for avoiding Zonks in making a connection are better with characters with fewer appearances.