I guess the only way to prove a near death experience to a skeptic is ....
.... for them to have one, and then have the faithful skeptics completely shut them down and tell them they know not what they saw or speak about!
My dad had such an experience. It dramatically changed him, and coming to Jesus after age 50 is not all that common, especially when you are brought up Christian Science, and believed the way the parents and church taught him.
After surviving his cardiac arrest, one by all accounts would have killed 99 of 100 men. In fact, his survival is recorded in the AMA journals because the City of Hope had never observed someone living through and recovering from that bad an attack!
He read the Billy Graham book [which I gave him after he was moved from ICU to CCU], and whatever it was he viewed in that NDE, changed him for life. As I said, he became a born-again SBC, and worked to convert my mom, and they both were water baptised [I drove all the way from Nebraska, where I lived at the time] to see it with my own eyes.
My dad spent the remainder of his life sharing Jesus, and he was extremely successful at reaching people for Jesus!
That kind of Damascus Road change comes at the expense of a major spiritual event, and I would never tell him he saw nothing, heard nothing or went somewhere in the time he was clinically dead [approximately 12 minutes].
What my distinguished colleagues seem to forget in arguing against near-death experiences, is that we serve a supernatural God. Supernatural means He is more than capable and able to do whatever He desires and wills, in order to demonstrate His presence, love and even conviction!
I do not think God gives a "hoot" when it comes to whether something He is going to do is in order with previously written scripture. After all, He inspired that which is written, and He surely can supersede that with His supernatural powers. I can't explain NDEs, but like a miracle, it is God's hand intervening in a life to have an impact in that live and the life of each person that k the one He touched.
In a way, Jesus did this during His ministry, always going outside the box, and it drove the Jewish leaders crazy. Do any of you truly believe God worries about what we may or may not think when he manifests a supernatural miracle of touch? He was, did and still is ready to do whatever it takes to influence people and groups for His glory and honor! That is what it means to be supernatural. To over ride that which is commonly understood or accepted!