JM had a £25,000 sweetener to find JB guilty. A very good reason don't you think ?
I think Julie Mugford was and could still be a nasty piece of work. Her behaviour then was inexcusable and I wouldn't even acknowledge her existence if she came to me for employment. Then or now.
And she knew how to look after herself, and make sure that number one was properly catered for. And I think she was always number one in her relationship with Bamber, despite Bamber being highly manipulative.
But,
It was the silencer that that the jury came back for more information on, so the Jury were not entirely swayed by her testimony. Then they went back for another 2.5 hours of deliberation.
There was enough truth in her statement/testimony to be able to trust
overall what she said. The bits that can be corroborated, like the existence of the phonecalls, are important facts in the case.
But with a friend like Julie, you don't need enemies. And I would guess that that still applies today.