Sorry to see what happened. Have you or anyone torn down the engine to inspect to see what let go and what was likely cause? I have a suspicion that maybe your Protune was done in summer and was pretty close to max. Certainly 19 psi is outside the efficiency range once you pass about 5,800 rpm, but not so at lower rpm. Was this a load target tune or a boost target tune?
If it was tuned in warm weather, then comes dense cold air, maybe she leaned out on you on at least one cylinder. My guess. I'd like to see what the top of the pistons look like. It could have been purely mechanical, like dropping a valve, which could happen to anyone, though. Just curious, and again so sorry for your situation. At least you were honest about it all. Thanks for sharing.