Proof of Heaven: A Neurosurgeon's Journey into the Afterlife

In a 2013 investigation of Alexander's story and medical background, Esquire magazine reported that before the publication of Proof of Heaven, Alexander had been terminated or suspended from multiple hospital positions, and had been the subject of several malpractice lawsuits, including at least two involving the alteration of medical records to cover up a medical error. He settled five malpractice suits in Virginia within a period of ten years. [11]

Esquire also found what it said were discrepancies with regard to Alexander's version of events in the book. Among the discrepancies, was that Alexander had written the cause of his coma was bacterial meningitis, despite his doctor telling the reporter that he had been conscious and hallucinating before being placed in a medically induced coma.[11][12] In a statement responding to the criticism, Alexander maintained that his representation of the experience was truthful and that he believed in the message contained in his book. He also claimed that the Esquire article "cherry-picked" information about his past to discredit his accounts of the event.[12]

Proof of Heaven was also criticized by scientists, including Sam Harris who described Alexander's NDE account on his blog as "alarmingly unscientific", and that claims of experiencing visions while his cerebral cortex was shut down demonstrated a failure to acknowledge existing brain science with little evidence prove otherwise.[13] Neurologist and writer Oliver Sacks agreed with Harris, and argued that Alexander had failed to recognize that the experience could have been the result of his cortex returning to full function at the outset of his coma, rather than a supernatural experience.[14] In 2012 Alexander responded to critics in a second Newsweek article,[15] where he said that he vividly remembers having periods of hallucination and explains that there was a massive difference between them and his 'fully immersive' visions of the afterlife. Alexander describes the hallucinations in his book, saying that they were disjointed and centred around both random events and his doctors. He then compares them to the "hyper-real" experience of the afterlife, and says they do not match up.