The person behind a familiar voice can change while the voice keeps granting them old permissions.

Familiarity issues permissions. A voice you have known a long time still gets the old access, the benefit of the doubt, the assumption of good intent, even if the person behind it has changed considerably. Trust attaches to the recognisable rather than to the current, which is why long relationships can go wrong slowly and invisibly.

With someone you have known for years, occasionally ask what you would think if they had said that today, as a stranger. Not to become suspicious, only to check that the permissions are still earned. Familiarity should be a starting point rather than a standing exemption.