Actually it doesn’t at all, for one if there were a case where someone was properly certified as brain dead as I mentioned earlier you think the author (who is not mentioned) would have mentioned it?
This author is basically saying that a person can still be alive without a functional brain. I don’t know about you but personhood to me is a lot more then then simple cellular function of my big toe. I’m sure one day we’ll be able to keep a body alive when the head has been completely removed, doesn’t mean that person is alive and I don’t see a difference when it comes to brain death.
In Catholic moral/ethical teaching, the time of death would be the time when the soul leaves the body. There is no test for this. Brain death criteria are considered a test as are other means of determining death.
If there are a dozen cases like the ones I heard about, it may seem like no big deal. None of these patients "recovered" which is a term used in this thread with no apparent definition or meaning. Nonetheless, if people can live without ventilatory support while meeting the criteria for brain death, it does call into question whether they are really dead or not.
Again, it may not seem important in the individual case but this is the beginning of the "slippery slope" of further defining death in terms of utilitarian criteria.