Just to recap:-
Jeremy calls police, relaying what his father told him, then police checked line at the scene and found it to be engaged. Later on, police asked operator to check the line at the scene, and she reports that the phone is off the hook...
At what stage did the phone at the scene change from being engaged, to being off the hook?
Who was still alive at the scene who was using the phone one minute, then left the handset off the hook, at a time when Jeremy was contacting the police from his phone at his cottage?
Jeremy claims someone hung up the phone at WHF and he heard simply an empty dialtone then the person immediately took it off the hook so that no one could call. He claimed he immediately dialed back but the phone line came up busy because it was sitting off the hook.
The telephone company said the phone at WHF was never hung up but rather that the phone call ended by Jeremy hanging up. This contradicts Jeremy's account. Moreover, if you hang up then immediately take the phone off the hook it will not disconnect a call. Both parties have to hang up the same time before one picks the phone up again or it takes 1-2 minutes of sitting on the cradle to clear.
Someone would have to have hung up, given Jeremy enough time to hang up and then to have taken the phone off the hook again. But the telephone company says this did not happen. The telephone company agent testified that the call was dialed from WHF, someone picked up at Goldhanger and the phone remained off the hook at WHF from that point forward. The person at Goldhanger hung up and cleared the line by the phone being hung up for 1-2 minutes.
The theory presented by the prosecution which the jury accepted was:
1) Nevill was injured upstairs in the inital attack and was unable to speak becaus eof his injuries so coudl not have made any phonecall
2) Jeremy took the phone, dialed his house and left it off the hook so it would keep ringing at his house
3) because he left the phone off the hook it kept ringing at his house the entire time he drove home
4) when he got home he answered knowing no one was on the other end but did it figuring this would demonstrate a call had been made
5) he hung up
6) after waiting a while to change his clothes or wash up he called Julie
7) after some more time he called the police
If he drove back to WHF and put the phone back on the hook he would have been far better off because then it would look more like someone could have made a call and then hung up from WHF.
Apart from the testimony from the telephone company being harmful because his claims were not possible, why would Sheila allow Nevill to dial (on a rotary phone so it would take longer to dial), allow Nevill to wait for Jeremy to answer (it would take Jeremy a few minutes to wake up and make it downstairs to the phone if he woke up at all) and then allow him to speak to Jeremy before suddenly taking the phone and hanging it up? Worse yet, why would she wait a sufficent amount of time for Jeremy to hang up then take the phone off the hook so no one could call back?
She suppoesly was marching him upstairs at gunpoint so why would she care if the phone kept ringing downstairs where no one could reach it? Especially since he already got the message out why would she need to leave the phone off the hook?
The phone calls were the worst part of his plan. They totally screwed up everything. He should have either gone back and hung it up, which he could have done before police arrived had he not wanted to arrive after them, or better yet should not have called police at all, should have made someone else find the bodies in the morning and acted surprised when he learned of it. Admitting he had knowledge of the incident means that when they proved Sheila didn't do it that he had to have been the one. But for his knowledge police would not be able to say who framed Sheila. They could say he had the most to gain but would not have any evidence he did it. By instigating himself in the finding of the bodies he gave evidence that would not have otherwise existed.
Instigating himself in the middle with his tale about leaving the gun out and shooting rabbits likewise was a poor idea. Not only because others contradict his claims and the claims don't make too much sense but the box of ammo was a really strong piece of evidence that he staged the scene. He said the box of ammo didn't move and that it had been full and thus was the source of ammunition used in the murders. The box had 30 rounds left though meaning only 20 missing. It can't have been the sole source of ammunition the killer either didn't use this box at all or used it as well as some from the gun closet. Why would Sheila go get 5 rounds from the gun closet and use 20 from the box? If she used 20 from the box she would have used 5 more from it not gone to the closet.
By trying so hard to say Sheila did it and ssaying he gave her knowledge of how to shoot and load the gun etc he was straining to frame her thus suggesting he framed her. SIlence would have bee far better because then he would not look like he did anything and they would only have bare suspicion because of a potential motive.
The last bit of evidence that he was the one behind the frame job was Julie, telling her anything was infinitely stupid. But for the phone call and the unconvincing rabbit shooting story that's the only evidence that there would have existed to suggest he was the one who framed Sheila.
So:
Leaving the phone at WHF off the hook and not going back in later to hang it up alerted authorities to how he faked a call from WHF, this fake call did not help him at all like he had hoped.
The supposed call and the mad eup story about how he was going to shoot rabbits an dleft out the gun and bullets for Sheila to find and how she watched him load it so she kne whow to do so made everyone very suspicious.
If he simply Killed them and framing her by leaving the gun on her and then made someone else find the bodies he would have been way better off. Calling police with the claims of receiving a call from Nevill ended up biting him in the butt bigtime. Trying so hard to make sure they put the blame on her by saying he left the gun and bullets out and all the rest made people suspicious because his claims did not ring accurate. If he let them draw their own conclusions and didn't go out of his way to finger her and pretended to have no knowledge at all he would have been much better off.
There is no way to establish Nevill made a phone call to police. The phone company said there was no record of any other calls and in fact the phone had been left off the hook since the call to Goldhanger so no subsequent calls could have been made. The police likewise deny receiving any such call and the written record that is trying to be used to suggest otherwise clearly states the son was relaying the message not Nevill directly.
There is no way an appeal court is going to believe it is possible Nevill made the call given the police testimony, records themselves and the phone company's testimony. It's a lost cause. Plus the court already rejected it only new evidence like a cop changing his testimony or some other cop claiming to have spoken with Nevill would be able to cause reconsideration of the issue. Short of new evidence there is no legal basis to reconsider the issue even.