I worked with non-verbal autistic people for about a year close to 20 years ago. Part of the approach at that time included facilitated communications techniques. My personal impression at that time was that there was no real way to verify that the facilitator wasn't responsible themselves, for the "breakthrough" in communication.
On the other hand... I am curious to know how similar the man's brain activity is, compared to a fully functional self aware adult. I think a more conclusive analysis of the man's awareness can be made from that data.
Doubt Cast On Man Found To Be Conscious After 23-Year Coma
"Remember that story about the guy who was supposedly revealed to be fully conscious (but physically paralyzed) and not in a 23-year coma? There are some serious concerns about the validity of that discovery, with some calling it bogus.
The problem lies in the main tool used to sniff out the man?s supposedly active brain, a technique called facilitated communication. Facilitated communication, in which a helper assists a physically disabled but mentally capable person to type out his or her thoughts, has been widely discredited for decades, after independent tests revealed that the technique is totally unreliable and often the result, conscious or not, of the assistant typing, not the patient. Basically, assistants would often pick up a patient?s hand and jam the patient?s finger into the keyboard, which I think we can all agree is not the most reliable form of communication"