Well, sure. That's easy. Tougher cases are like Terri Schiavo were there was (mercifully, IMHO) actually no brain left. No possibility of having had awareness for all of those fifteen years. But there was no way to know that until after her body "died" and an autopsy could be performed. We're not good at that. The difference between a body that's just an unoccupied meat machine, and a person that's still aware and "there" is not something we're very good at defining yet.
I was reading a few new articles not long ago of Dr.s who are working at better ways to determine death in situations as this. It was interesting because there does remain still opposing ideas...and both sides are convincing.
In this mans case I want to hear more of the story as to just how vegetative was he...there are varying degrees of this as you likely know.
Are you freaking kidding me? “No brain left” indeed. You have drunk the koolaid