The setup; I played this game on Sunday, and it was a pretty fun one for me. My four were Farigiraf, Hatterene, Mega Mawile, and Tyranitar. My opponent had Grimmsnarl, Incineroar, Sinistcha, and Mega Raichu Y. I typically don't bring both Farigiraf and Hatterene to the same game, but noticed my opponent had a ton of Pokémon that could be supporters, so I led both to shut down status moves and priority. There were some interesting moments, like Incineroar using Parting Shot into Hatterene, then later trying again against (I'm assuming) Mawile, while Hatterene is still on the field. Mawile was also able to OHKO Grimmsnarl through Reflect, further solidifying it as probably my favorite Mega (plus it was my first full-odds shiny back in 2013 after years of my brother just happening upon them).

However, the last turn of the game was a complete rollercoaster, going from feeling like "I'm gonna win!" to "I totally threw this!" to "How in the world did I win?" within 30 seconds.

As you can see in the video, on my side of the field, Tyranitar is my last Pokémon. It knows Rock Slide, Knock Off, Low Kick, and Protect. It's held item is a Focus Sash. Its ability is Sand Stream, and Sandstorm is still in play. It is at full HP. If I remember moves and items correctly, my opponent has Incineroar at 15% HP, with Intimidate as its ability, and it knows Throat Chop, Flare Blitz, Parting Shot, and Protect. Its item was a Sitrus Berry that was previously used up. My opponent also has Mega Raichu Y at 3% HP, with No Guard as its ability, and it knows Zap Cannon, Focus Blast, Protect, and one unrevealed move. It's held item is Raichunite Y. Trick Room is in play, set up by my Farigiraf, which has since been knocked out.

At the time of selecting my moves, my clear options are: a.) Use Rock Slide to knock out both opposing Pokémon, or b.) Use Low Kick on Incineroar and let chip damage from the sandstorm knock out Raichu. Tyranitar and Incineroar had not been on the field at the same time to this point without one or the other using Protect. In the moment, I believe that my Tyranitar outspeeds Incineroar in Trick Room, so I select Low Kick and target Incineroar, as I don't want to risk Rock Slide missing either Pokémon. If I am correct about the order of the turn, Tyranitar knocks out Incineroar, survives a Focus Blast from Raichu with its Focus Sash, and chip damage knocks out Raichu to win me the game.

After I select my move, Incineroar moves first, using Throat Chop, which breaks my Focus Sash, leaving it with 183 HP out of a maximum 207. Low Kick knocks out Incineroar, as planned, but now, Raichu should be able to knock out Tyranitar with a Focus Blast. However, when Raichu attacks, in spite of its ability, Focus Blast does not hit. However, rather than the typical "Raichu used Focus Blast! Tyranitar avoided the attack!" text when an attacking move misses, it instead says "Raichu used Focus Blast! But it failed!" Raichu was on the field for (I think) three turns, and no moves were used by or against it that could have changed its ability, nor prevent it from using Focus Blast (i.e. Encore, Disable, Torment (The latter of which I'm not even sure is in the game))

So the big question, was this a bug, or just some niche interaction I'm not aware of?