A cardiologist friend of mine did an extensive study of heart patients that were revived after heart surgery. He found that approximately 18% of the patients remembered experiencing leaving their body during the surgery.
The key here is “remembered” as the drug Versed is often given to block memory recall of experiences while under anesthesia.
They use it on me recently as twice before I popped back into full awareness during two different major surgeries while my arms were still strapped to the boards and intubation was still in me.
Anyway, my friend’s research was so good it was published in the medical journal Lancet.
” Near-death experience in survivors of cardiac arrest: a prospective study in the Netherlands”
Dr Pim van Lommel, MD
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(01)07100-8/abstract
Would you care to be specific, and name your friend? Perhaps there are other articles / research?