The common advice if you are caught in a narcissistically abusive situation is RUN!
Personally I believe this is not always possible or even adviseable. I just came across a video today called ‘Walk Don’t Run’ and I thought this was the best advice I had heard. He makes the valid observation that predatory animals instinctively chase, if you run. He points out that the standard advice you are given, if you suddenly encounter a predatory animal is to back away slowly.
Getting away from predatory people is much the same in my view. Don’t turn your back. Just try to back out slowly and carefully, until you get a safe distance away..