A lot of discussion on Neville's call to Jeremy has been on why Neville would not phone Jeremy. However what is the main reason he would phone ?
Despite several options, Neville obviously felt Jeremy was the best option. Rather than telephoning other relatives, waking June, or telephoning the Foakes's. And a better option than the police unless you believe Neville actually called them.
Neville hoped/expected Jeremy to rush over, force entry into WHF and restrain/calm down Sheila. As well as not involve the police as Neville liked to keep things private.
Quite why Neville and June could not restrain/calm down Sheila themselves I do not know. If they couldn't, there is no reason Jeremy could if/when he arrived at WHF. Neville was also putting Jeremy in danger.
Why did Neville make such a very very bad decision ?
Jeremy did the complete opposite to what Neville expected/hoped. Ringing the police after 26 minutes and then not leaving his cottage until phoning Julie and putting on several layers of clothes. Then driving very slowly to WHF, rather than rushing over.
Upon arriving at WHF he made no attempt to go within 50 feet of WHF. Unwilling to attempt to restrain and calm down Sheila as Neville hoped/expected. He failed to tell the police he knew of ways inside WHF.
Perhaps Jeremy was scared and confused. Which is understandable. Neville obviously felt he would be brave and focused, willing to risk his own life and attempt to save his family. Although Neville would have to leave the front door open for Jeremy, something he did not do.
Jeremy also had a very poor relationship with Sheila. Telling the police she would not be pleased to see him and saying several distasteful things to the police about her. Admitting himself decades later he did not understand her illness. Surely Neville knew this. He was both their father.
Neville was not stupid and knew Jeremy better than anyone. Why do people believe Neville made such a bad judgement call in such a serious situation at 3am ?