This isn't concrete, but to me, it's very suspicious of toggling with yen.
Link to clip
The argument for him toggling here is:
He jumps left and brings down the 1st Soldier to ~130 HP, but then despite his Soldier bombing, he jumps back and hard flicks (looks like a lock on) to the 2nd Soldier. Then flicks right back perfectly onto the 1st soldier behind the rock.
The problem is what would you do that? You brought down the 1st soldier to 130 HP, and you know your Soldier is going to bomb, so why bait? You wouldn't.
I think what happened was, yen wanted to fight the first Soldier, but he toggled so his crosshair locked onto the 2nd soldier, then because he wanted to fight the 1st Soldier, he locked back onto him, jumps towards him, but the Soldier jumps out so he recommits on the 2nd Soldier.
It is wrong to say this is concrete evidence, but it's suspicious. There is no reason for him to do 80 dmg to a Soldier, lock onto another one perfectly, and lock back on to the original one perfectly behind the rock. A cognitive player would have continued pressuring to get the Soldier picked, made the space, and followed up for his bombing Soldier.