I believe they are real in the sense that they have experienced a real hallucination or dream. Unless the brain is instantly blasted into tinny pieces, the brain won't shut down instantly. It's not weird to think there is a short time in which our senses are so surpressed (due to dying) that we can experience the weirdest dreams in our last moments. And I also think that the actual dream or hallucination at that time is something very abstract, many of the gaps and meaning might not be filled until after our ressurection. Buddhism deals with death, ressurection, and life achievements. If the buddhist guy believed he did not do his best in life, likely he would fear death. Having a near death experience he would no doubt experience that fear in a very surpressed way, and after ressutrecting, he put context to that fear and remembers what he thinks he experienced.
I use a personal dream and the deja vu phenomenon as an example that works similarly. I once had a dream, I didn't think much of it, something happened in real life and to me at that time, it was exactly as it happened in my dream. Obviously, my dream probably had similar aspects, and my brain just did the 1+1 and combined my real life memories with the memories of the dream, creating a very deja vu like I see in the future feeling.
Also, I am skeptical about those NDE's that have had outer body experiences and could remember everything surgeons have said and specific details about the room despite never having opened their eyes in that room.
