Regardless, it doesn't matter because Progenitorial Wrath is random anyway, and has a chance of hitting any party member, and you just got unlucky.
The only thing you might've missed are a few upgrade items, -sol's and weapons, all of which that you can buy later in the game anyway, so there's not really any real point.
I knew it was random, but the battle went so long he always used it on Lightning at one point. I couldn't go back and grind either, I saved in the 'waiting room' place. I tried, but I couldn't.
I want to get all the trophies anyway.
Progenitorial Wrath is the reason I'm currently taking a break from the game. It got me twice, both times he was nearly dead.