I can't discount the possibility of a bad primer, but the primer seemed to have had enough "ooph" (for lack of a better word), to drive that 158gr jacketed bullet into the barrel beyond the barrel cyl gap. I doubt you will ever know the reason.
Recently had a similar experience. It was my fault. I loaded a batch of 45 ACPs w/200gr LSWC and 5.0gr HP38, Win LP Primer. After loading, I put the batch in a big bowl filled with water, dish soap and vinegar and agitated by hand to clean them up a bit.
At the range, I was shooting a FA97 with a .45 ACP Aux cylinder when I got an unexpected misfire. Couldn't cock the hammer or turn the cylinder and knew immediately what had happened -- bullet stuck between face of cyl and barrel.
A long time ago, I bought a "squib load rod set" from Brownells. It was an easy task to move the bullet back into the cyl/case and the case out of the cylinder. It turn out that the case was split, and when immersed in the cleaning solution, it must have contaminated the powder.
Old "Murphy" is always sitting on everybody's shoulder just waiting to screw things up -- you need to be constantly aware of things that don't sound/feel right.
If you shoot enough, even the most vigilent will ultimately experience the unexpected.
FWIW,
Paul