I'm not sure that's right. Dead is dead. The pronouncement of death occurs because there were no signs of life apparent to the outside observer. Your argument for the patient not being dead depends on future events, which cannot be known at the time of the observation.
If, for example, the patient were dropped into a vat of liquid helium, all electrical and chemical activity would stop. There would be no question that the man in the vat would be dead to any observer. If we adopt your interpretation of death, whether the man were actually dead or not would depend on whether future medical science advances to the point where someone could be revived from being deep frozen, and then whether this particular person was.
Then, if you decide that the person is not dead because he is later revived, you have to ask where was he in the meantime?
“Your argument for the patient not being dead depends on future events, which cannot be known at the time of the observation.”
That’s right.
Are you suggesting a seance to determine the difference in experience between those who come back, don’t die, and those that actually die?
That would be a great study design, but in a practical sense it might be hard to do, or trust the data.
On a broader level, your argument and example of the frozen suspended animation is interesting, but it is philosophical, or semantic, only peripherally related the the question trying to be answered by this study.