I have outlined the time-and-motion flaw with Sheila in the Crown's case on a different thread. If the Crown cannot establish that Sheila was under sedation, then I think the flaw could be fatal for the prosecution.
The issue with Nevill is of a similar kind, and while not as serious for the prosecution, it raises questions.
The relevant points are:
(i). The Crown deny that there was any 999 call from Nevill.
(ii). The main stairway is steep and narrow.
(iii). Two spots of blood were found between the main landing and the kitchen, respectively on the wall of the mainstairway and on the jamb between the foyer and the kitchen.
(iv). There was no blood on the kitchen door.
(v). There was no blood on the kitchen phone.
(vi). There was a struggle in the kitchen between Nevill and the killer.
(vii). Nevill was shot upstairs, roughly four times according to the Crown, and then four more times in the kitchen.
(viii). Nevill moved himself from upstairs to the kitchen - according to the Crown.
I find it difficult to reconcile all this with Jeremy being the killer, simply because in those circumstances:
(a). Jeremy would have already fired at June upstairs and left her seriously injured.
(b). Nevill must have been running for the kitchen phone. Why else would he run for the kitchen rather than stay upstairs and try to save Sheila and June?
(c). Nevill was already gravely injured, according to the Crown, yet he is able to move from one part of the house to another with the killer in pursuit.
Was there something else, other than the phone, in the kitchen itself or something in a different part of the house that required him to go via the kitchen?
If Nevill is running for the kitchen phone, then this does not have to be a completely rational decision. Nevill, we assume, is injured in the face/jaw, but it doesn't follow that he would not try to dial 999.
If there is no blood on the kitchen door, this suggests that the kitchen door was already open and Nevill does not try to block his attacker by shutting the door behind him.
If there is no blood on the kitchen phone, then this means Nevill never reached the phone.
Yet Nevill has left behind his wife and daughter, and is injured, because he wants to reach the phone.
There are blood prints on the worktop near the phone.
It seems to me there are two main possibilities:
1. Jeremy was the killer and caught up with Nevill just as he reached the worktop. They then struggle (or whatever happened next).
2. Sheila was the killer and the kitchen struggle occurred at the beginning of the incident. Nevill is already injured and goes for the phone again but Sheila stops him.
I have to say that 2 does seem to me more credible. If Sheila was the attacker, Nevill would have been quite hesitant about what he was doing, especially if it was early in the incident and he had already spoken to Jeremy.
The problem with 1 is that, if you look at the position of the prints and also consider the narrowness and steepness of the hallway stairs, Nevill had the advantage and would surely have reached the phone in any event. If Jeremy had already opened the line, all Nevill had to do was replace the receiver, take it off again, and dial three digits - which takes seconds. Thus, not to touch the phone must have been a choice - it's much more likely he makes that choice for Sheila rather than Jeremy.
There are two ways the Crown could overcome this:
Solution 1: Nevill reached the phone but the abortive/broken 999 call was not recorded at that time; furthermore, even if the line had remained open at the caller's end, it would have been terminated by the operator after a short period of time, and no further investigation would have occurred. Jeremy took it on himself to wipe the phone clean of blood, thinking that blood on the phone would be inconsistent with the staged call from Nevill.
Solution 2: Nevill reached the phone but Jeremy stopped him just as he was re-dialling. A police officer used the kitchen phone on the morning of the 7th., wiping it clean of blood, and this has never been recorded or admitted, perhaps because only one officer was aware of it having happened and he didn't realise the significance of what he was doing at the time.
Solution 1 can only be confirmed by somebody with knowledge of how emergency calls worked at that time, but in any event, this gives me another thought about a possible kernel for Jeremy's idea of staging a call from Nevill.
One theory I have is that he got the idea due to a genuine call from Nevill that I hypothesise was made the previous evening and that may have catalysed his rage, but there is an alternative possibility.
It's possible that Jeremy got the idea for staging a call after terminating Nevill's abortive 999 call. This may have occurred to him due to the fear (whether justified or not) that the police could and would trace back Nevill's unsuccessful call and so he decided there and then that he would have to stage a call from Nevill to himself, thinking (rightly or wrongly) that this would somehow cover him. He then realises also that a call to Julie may help him, so he rings her at about the same time that he rings the police.