Would attacks like Shred/GMax Pulverization trigger Torracat's Gritty Claws?

[XanXic]

So I'm more asking to get an official ruling. I was playing PTCGL and had an interaction that was strange to me. It's not an airtight I know but still.

Anyways. My opponent attacked me with Torracat - SWSH12's attack Gritty Claws which is "During your opponent's next turn if this Pokemon has full HP and would be Knocked Out by damage from an attack, it is not Knocked Out, and it's remaing HP becomes 10." I did my turn and attacked with Duraladon VMax's GMax Pulverization. The Torracat didn't get moved so the effect was still in place and it had full health.

When I attacked the Torrcat died and did not end with 10 hp remaining. My opponent was also surprised going by their numerous "what?" emotes. I guess I would get why in theory since the damage can't be reduced and in a round about way reducing it so Torracat has 10 hp left would fall in that line. But the wording seems to be you would give it back 10 hp during the KO check "phase" after you finish your attack. I'm just wanting to know if this interaction follows intention or not.

 

[PokePop]

We're here to give official rulings!

Before I read your question, I'll say that PTCGL and PTCGO have bugs and occasionally you'll see strange/incorrect interactions.
Now, on to your question.

It's a bit hard to say without knowing what other cards and effects were in play that might have altered the result, but just based on the interaction between these two cards, you are correct. It should have has 10 HP restored. I'm guessing the program read the text "This attack’s damage isn’t affected by any effects on your opponent’s Active Pokémon." to mean it should ignore the 10 HP restoration, but that is incorrect.

There is a ruling in the Compendium on a similar interaction:

Pokémon Rulings Compendium

Q: If the Pokemon that Focus Sash is attached to is attacked with an attack such as Cobalion EX's "Steel Bullet" that ignores effects on the Defending Pokemon, is it Knocked Out? A: No. The full damage would be done first, and then afterwards the effect of Focus Sash would reduce the damage...

compendium.pokegym.net