That's what this report is saying: She was diagnosed as being in a vegetative state, which meant even when she was awake, she was unresponsive. ... When the scientists compared her brain activity to that of healthy patients, who had been asked to carry out the same task, they discovered the patterns were "indistinguishable".
Bottom line? It's easy to assume that science knows what it's talking about, e.g., diagnosing a permanent vegetative state. But ask a neurologist sometime and you'll be surprised at how much more they don't know. Science is like that. It's a process of discovery by observation, and the instruments to gather data are never perfect nor extensive enough. If there's reasonable doubt, then we cannot make that decision to do something that cannot be undone: like ending someone's life because they might never recover.
Update: Amy Welborn posts more on this, with a link to another post by Wesley Smith. A question that just occured to me: did they do MRI on Terri Schiavo? From what I remember, no. They just did a CT Scan, something which drew strong reactions, being insufficient in their expert opinion. Ahh.. lots of things about Terri's demise are mind-boggling. Here's praying that Medicine will catch up quickly and avoid cases of sending people to their deaths too soon.
Update 2: From Wesley Smith's comment box comes these gems:
So, if you are unconscious, dehdrate because you are not a person. If you are conscious, dehydrate even more urgently because you are suffering. Heads we win, tails the disabled person loses. [WS]
It comes down to this: Can we love and care for imperfect people? [B]