Yes, but the scientific method also requires observational experience for proof.
It is true that hallucinatory drugs have induced so-called mystical experiences. However, there is no other way to know what occurs in consciousness after death other than observational accounts given by those experiencing NDEs. The anecdotes are all that we have to go by. (I'm reminded of the movie Flatliners
) If the anecdotes describe similar experiences, is it not reasonable to assume that upon death, we might also?