I worked for a short time in a hospital but did not have any of the experiences you write about. I have talked to a nurse that was keeping a book on the near-death experiences but she seems not to have anything you described.
Anyway, we live to be in the service of our Lord. By being alive, we are always called to do His will. You conclude that his being alive after the shortness of breath was for him, but I can say that it could have been for you. His purpose for a second-chance could have been for your faith and your family’s. God grants us what we need even though we don’t always know what it is.
Please see this experience as a gift to the family that they could be together in faith and prayer and be with him in a holy moment.
mdcpensive1