I agree OP, these are two distinct experiences.

I think Terence McKenna was on the right track when he said the mushroom has an agenda. It is an alien intelligence that moves us into it's reality to teach us concepts that we have not encountered on our version of reality. But they do not give us an overall picture, just a slice.

NDE's, on the other hand, are a result of the divisions between the soul/heart/mind being dissolved so that you experience clarity about the nature of reality. This is much more encapsulating that any 'trip' and although the imagery may be confusing, the essential message is coming directly from your higher self, not another entity.