I would think it depends on your circumstances. In the city or suburbs I agree, build a fence your dogs can't get out of. If you farm 160 acres, it would be beyond reasonable to suggest someone put up a dog proof fence around the property. In some circumstances, dogs are used to keep non desirable animals at bay and have free run of the place. Yeah, they are going to wonder on occasion and yeah, when they go somewhere they shouldn't they could (and should in some circumstances) get killed. The point though, is that all situations do not fall under one set of rules or responsibilities. Sometimes bad things just happen.
As to accepting responsibility, it looks to me like the OP is doing that. I see no need to point out something that is already known.
Well said.
It is not common in America that we put fences around our front doors. Expecting that is unreasonable.