What utter tosh! Do you really believe that Julie MADE Jeremy break into that office? Do you really believe he was so weak. I think being besotted by Julie can be ruled out of the equation.
I think Bamber himself puts this idea to bed himself Jane, Julie would have been guilty of knowing he’d done it and probably went along with the idea, but to honestly believe Julie had this much coercive control over Bamber is rubbish.
This shows the type of Greed within Bamber, to Rob your own family, a family that had given him everything, yet it still wasn’t enough. This greed he had was the sole purpose why he chose to kill everyone, he’d had access to the Wills since a very young age, something he would have checked regular for any updates, he knew to the word what was written, He was worried that June was going to change her will and leave it to the Church, something Brett and Julie both touched on, that’s why it had to happen before she changed her Will.