I'd said the poker years ago too as nobody in their right mind heats the end of a rifle over the fire,nor does it get red-hot after firing,well certainly not as hot as to cause superficial burns as shown. Whereas a poker if it's been left in the heat will retain that heat.
Blimey,JB hadn't hated his parents that much to have inflicted such injury,I don't care what anyone says.
Only someone deranged and unbalanced would have even thought of such harm to another human .JB hadn't/hasn't got it in him.
Now if JB had planted JM when she threw things at him and put a pillow over his face, I would have questioned his retaliative behaviour. JM couldn't show any injuries caused by violence in their 18 month courtship. Speaks for itself really.