For me the point wasn't that much about enabling more domestic violence, but about being "in the loop" of that particular incident.

Also, yes, it is worse when the person is drinking out of the home, because that means family members have a lot less control over the drinking and less warning.

And domestic violence really doesn't have a high requirement of blood alcohol level. Even very minor levels can disinhibit a person, especially if he is already habituated to act out on his family members.