When I ghostwrite an autobiography, first-person POV is the only option I consider and for that very reason. Gifted Hands that I wrote for Dr. Ben Carson begins like this:
"And your daddy isn't going to live with us anymore."
"Why not?" I asked again, choking back the tears. . .
In 90 Minutes in Heaven, first person made sense because the entire book revolves around Don Piper and what he experienced.
I've written a total of four books for Don Piper. The other books carry Don's name and mine, which makes me the co-writer. Our editor insisted on staying with the first person and I had no problem with that. Chapter 66, for example, from our second book, Daily Devotions Inspired by 90 Minutes in Heaven, begins:
I survived because of prayer.
I survived because one man felt God impress on him to pray for me, even though the EMTs said I was dead. He prayed anyway.
First-person narrator is an observer
and also a character or participant.