Type of Spiritual Experience
I don't think this was a rebirth. During rebirth experiences you do not see people you know. And he had no helpers, in even the most alarming of rebirth experiences there are nearly always helpers present. But I do think it was a vivid vision designed as a wake up call.
The source sadly gives no indication of what he was doing at the time
A description of the experience
Margot Grey – Return from Death [from Maurice Rawlings]
I remember more clearly than any other thing that has ever happened to me in my lifetime, every detail of every moment, what I saw and what happened during that hour I was gone from the world. I was standing some distance from this burning, turbulent, rolling mass of blue fire..... I saw other people I had known that had died.... we recognised each other, even though we did not speak. Their expressions were those of bewilderment and confusion. The scene was so awesome that words simply fail. There is no way to escape, no way out. You don't even try to look for one. This is the prison out of which no one can escape