Is it possible for a person who has suffered brain death to regain his life?

Q: The claim by the doctors—may Allah preserve you—that a person who has suffered brain death cannot regain his life?

A: This claim is not to be relied upon and is not acted upon, and there is no evidence for its correctness. It has reached me that some of those who were said to have died from brain death had their life restored and they lived. In any case, brain death is not considered, and the ruling of the dead is not applied to its owner until his death is confirmed in a manner that leaves no doubt.