Obviously, no one can legitimately deny that someone had a subjective experience. However, that doesn't imply that the person who had the experience is best qualified to explain the experience, just as a patient is usually less qualified than eir doctor to diagnose eir illness. The afterlife is an explanation, and it's one that multiplies entities beyond necessity, given our current information about the brain (that it can experience a large variety of hallucinations and other misleading perceptions). Nothing indicates that consciousness can survive when the brain is no longer fueled by the body's metabolic processes. For the afterlife to be a competitive explanation for NDEs and the like, we would need other information suggesting that consciousness could be separate from the brain.
13 years late here, but I think there's a place for this distinction.
When someone says "I experienced such-and-such when I was near death, and that proves <something spiritual>", there are 2 places for doubt that RobinZ is distinguishing.
RobinZ is distinguishing between those two avenues of doubt, whereas you're apparently grouping them together.
I was on Reddit today, and I came across (this link)[http://www.reddit.com/r/AskReddit/comments/eyiat/for_those_of_you_who_have_died_and_been/]. One of the things I've seen on this site that's bothered me is the exclusion of personal experiences in deciding what a person should or should not believe. I know that less wrong is mostly atheist, and I wanted to hear less wrong's reaction to descriptions of experiences like these.
For example, my dad was in the hospital 5 or 6 years ago when a truck came across an icy road and hit him head-on. His most vivid memory from this is a dream he had when he was in the hospital. He was in a pool of water with my mom, and they were both naked (they were underwater, but didn't need to breathe). He remembers that at the end of this pool, there was a bright light that he wanted to head towards. He began to swim that way...and here, I don't remember what happened, but he was unable to reach the light for some reason.
Such stories seem to be common for people who come close to death, and for a community based around rationality which seems to consider the likelihood of life after death as slim, I just wondered what your reactions are. My reaction is that such experiences are explainable in terms of neural activity, but that doesn't necessarily exclude the possibility that these are descriptions of experiences of an afterlife. I'm not convinced by them, but I do consider it to be possible.