[WillAdams]

Driving along the (not gated) driveway of a home, walking around the perimeter of the property (which did not have a privacy fence, the legal terms here are "curtilage", public right of way, and easement) and hearing a cry for help and acting on it are not an invasion of privacy.

All of this was of course, a long time ago, and a further consideration was that the family whose phone was used were on a party line with the neighbor in question and specifically mentioned that a phone call for that neighbor went unanswered the previous evening which added some urgency to the matter.

If anything, Japan has a culture of privacy and respect of individuals which make this originally noted societal problem more likely.