I'm starting to reload and those pictures give me pause, as they should....
Yes, reloading is serious business.
I would like to have examined that pistol, that is not a normal overloaded case situation, as someone else stated, a powder mix up perhaps? h110 or ww296? Experimenting?
My 1st thought was squib, and then another round behind it, next thought was the pistol had a feeding problem, and the bullet got shoved way back into the case and was then fired.
Most .45 acp's don't have supported chambers, especially 1911's, and if you look at the 2nd pic, the case head nearly completely separated, and has been stated earlier, the lower portion of the case under the feed ramp will blow out and become the relief valve, not enough to save a barrel, but a slide blow out is rare. I hope He pays more attention from now on. That hand is going to get his attention for some time for sure.