Nevill would have disarmed Jeremy, injured or not, he'd served in the war so I'm sure he'd have been used to surprises and would also have landed him a punch or two----not forgetting that Nevill was a strong man.
Confronting a woman, his own daughter would have been a different scenario as I honestly don't think that Nevill would have realised that she'd carry out what she must have threatened beforehand as the shots were indiscriminate even at close quarters------the type of shots which weren't afforded to someone who was used to firing a rifle.