I feel there are situations in which it would be justifiable to hit/smack or even kill someone. I do not adhere to the flawed legal system for this, I do not trust it, I think for myself.
A friend has been regularly beaten up by partner they have been married to for several years, including hospitalisations one of which was life threatening. This friend is too afraid of leaving. If i walked in and witnessed this abuse and believed the friends life was in danger i would think nothing of hitting the abuser over the head with a heavy/sharp/blunt object. This would be on the assumption that i personally knew the details.
This friend could be male or female and i would act in the same way.
There are many other situations too.