You would agree with me that it's not in all cases.
What happens for patient A may not be same for patient B.
I agree with you some patients are responsive.
However, in this context, the "only" was used to emphasize the time we can ever say man have no senses or rather if they do they can't express it for observers(like doctors) to record.
RE: THE DEBUNKED MYTH ON THE FIVE SENSES OF THE HUMAN BODY.