Has anyone ever heard of this happening with LCP's before? There must be a million of those little guns out there. If this is not a rare occurrence I would think that we would have heard about it by now. My guess would be an ammo issue. I certainly hope so anyway.
If it was a squib load and one round was still in the barrel, it would not have generated enough pressure to cycle the slide. In that case, he would have had to do it manually. Does anyone remember if that happened? From the description of what happened it sounds more like a double charged load.