No, the castle doctrine affects what people do in the moment ... not drawn out over days after.
It wasn’t self defense, it wasn’t resisting robbers, it was sadism.
Once he had them tied up he should have called the cops and it would be over.
For what he did after that, he deserves a harsher punishment than the laws likely allow.
That isn’t saying the robbers don’t deserve to the lawfully punished after a trial before their peers... they just didn’t deserve to be ****ed in the can over and over by some giant asshole.
Then he should have just killed them.
Im fully on board with killing criminals who break into homes. That they have life is a blessing.
That, in this case, was actually mercy.