The timing of the second telephone call to Julie was irrelevant insofar as one would expect even Jeremy to make sure he did not drop a clue that his family were dead before he himself knew through the purported call from his father that "there's something wrong at the Farm". As it was Julie went back to bed knowing full well for those few ghastly intervening hours that all occupants of the Farm were dead,though she was not at this stage cognizant of whether Jeremy himself or a proxy was the culprit. One of the questions Jeremy lamely answered during interrogation was why did he telephone Julie at all in the middle of the night,when he seldom took Julie's advice on any other matter. The only explanation I can see which fits is that he wanted to tie Julie in as an accessory,along with the excuse for having the ladies' bicycle at Goldhanger which no lady had used covering herself in mud,and of course the sleeping pills which he had taken from Julie to attempt to drug his parents on a previous occasion.
Of course when Julie went to the Police Jeremy had only two courses of action open to him:either admit the murders and rope Julie in on the scheme or to bluff his way out of everything and claim innocence. One post I read today was that Jeremy's Defence team made mistakes. Of course the did:they were all public school types with their noses in the air most of the time thinking they could bluster their way out of everything. Unfortunately they were up against another public school type in Mr. Justice Drake who being himself an ex RAF Officer must have felt an affinity with Nevill Bamber and did his utmost to secure a conviction.
The late Edmund Lawson went to a comp. Perhaps if he hadn't have done he might not have got lost en route from court to the shooting range

By getting lost he missed a vital opportunity to observe jurors witnessing the event of shots being fired with and without a silencer fitted. Come to think of it couldn't it have been reenacted inside a building? Surely the army/police must possess such buildings for training? Oh I forgot wasn't that what WHF was used for?
I have no idea about Geoffrey Rivlin's schooling. I know he usually practised on the Northern circuit and normally acted as a prosecutor.
At '02 CoA it was Michael Turner's first case as a newly appointed Queen's Counsel. As we know we all have to start somewhere. But there appears to have been a real mismatch in terms of experience etc between prosecution and defence.
I might start a thread on the above to compare backgrounds, experience at time of acting for JB, notable cases etc.