Then my idea might be worth trying.
No, your 'idea' is founded in an assumption that the brain organ is the primary defining form with which to convey the status of human being. You would define the organism based on the functioning of the organ, the brain. The entire point of the brilliantly constructed essay is that the coordinated whole of the organism is what defines human being status and it is the coordinated wholeness that is gone when death is scientifically declarable. As you know, the brain is a coordinated functioning organ of the organism only after birth, by several months if the perspective is language acquisition.
The ability to act as an integrated whole is the only function that departs from our bodies in the moment of death, and is therefore the defining characteristic of "human life."