Took a look at the book and some of the reviews on Amazon. There are some ways in which Donahue’s efforts could clear the air.
One would think the aural experience of those proximal to the event would easily hone in on differing sound and location for each shot fired. A shot fired from a building 100 yards away elevated would sound considerably different than one fired from a car passing 25 yards away on the ground. Maybe Donahue’s work explores and explains that angle. I would think the result of a bullet passing through soft flesh vs. a bullet striking the skull would differ considerably as well in the way of fragmentation. Just my amateur thoughts.
The book also covers the “aural evidence”. The book covers the trajectory angles too.
Your amateur thoughts approach professional level compared to my amateur thoughts.