If you could figure out by my sig, I'm an "XD Guy"...
I have had XD's and XDm's apart hundreds of times and know them pretty intimately. I cannot see any way that the XD firing pin could EVER come in contact with the primer out of battery unless all the safetys on the gun were somehow bypassed or modified in ways that make no sense whatsoever in the performance of the firearm. Even then the firing pin and the channel it rides in are very robust and bending it in a manner that would strike the primer would mean that it was bent and lengthened considerably while retaining the same diameter at the same time. Physics rules apply.
My best guess would be a double charged handload. This XDm is a .40 and at 35000 CU's Max pressure that is a hot number for such a large caliber round. It is sooooo easy to make mistakes, especially with a progressive reloader... or even setting your digital measure or scale when loading by hand. I've seen plenty of large frame all steel .44 Magnum revolvers double charged with powder with the top strap and cylinders blown to bits so steel or polymer doesn't matter.
Be super careful, especially when loading "mouse fart" loads quickly because when 4.9 grains becomes 9.8 grains of powder there is a little difference in chamber pressures!

Other possibilites are a blocked barrel or a split case... You make hot handloads in an auto in the same cases over and over and they can get kinda thin. Add to that the ramped section of the chamber that isn't fully supported to allow for feeding... The explosive power of the powder will follow the path of least resistance... right out the bottom of the case in the feedramp. The pics look like that is a possibility too.
Just my 1 1/2 cents,
Respectfully Submitted for Your Review,
Scott