Hi Steve,
I'd tend to believe IF Neville did pho e Jeremy it would of been more of a case of him not wanting others to know about the extent of Sheilas illness, did he kno len foakes or colins number off by heart? He knew Jeremy was close, I don't believe their relationship was as tempestuous as some would like us to believe in my opinion.
But by the end he was in fear of his life, to which the remark about the putative shooting accident to Barbara Wilson attests. Jeremy had enjoyed two foreign jaunts at his parents' expense and the bills were adding up, June herself refusing to write any more cheques in his favour since Easter.
It's under these circumstances that the crimes must be evaluated: the separation from the birth mother, the bonding with June only to be sent away for eight long years, June's illness again followed by Sheila, then Sheila's illness two years later. It's no wonder Jeremy began to feel he was the only sane one amongst them ,especially after Nevill's moroseness and infirmity at the end.