Whether he is dead or not has no bearing on anything.
Also, John Mack has no bearing on your post at all as Bassett was only associated to him for 4 months. To use that short period of time as to give Bassett some mantle of credibility is ludicrous and disingenuous. We have no idea what Mack felt about Barrett. That Barrett was involved with him for so short of time does not say a thing.
Mack himself did not believe in the actual physical reality of aliens. He felt alien abductions and visitations were transcendental, spiritual encounters akin to a vision quest. All in all he took aliens and turned them into psychobabble woo.
So using John Mack as an expert does nothing for anyone's contention that there are aliens visiting the earth.
Facts don't lie or have an agenda. Facts are just facts
"God did it" is not an argument. It is an excuse for intellectual laziness.