Though I do not think THIS is valid evidence to support the notion that the caliber and load you choose for personal protection does not matter, it does somewhat coincide with several things I have learned over the years, particularly when it comes to testing in ordnance gelatin.
1. There is not a tremendous amount of difference when it comes to the terminal performance between modern loads for the 9, 40 and 45.
2. There are many things that influence if and why a single shot from a handgun is successful at stopping an attacker.
3. Shot placement has a lot to do with it.