He obligingly adjusts his grip even though it makes him bend his arms really weirdly and makes it harder to hold the whatever-it-is steady. Though it doesn't seem to need him to hold it at all. What's important is that she clearly knows what she's doing and he's helping! Faro drops down onto his knees as she leans more heavily on the chisel so she's got more room to lean.

It's a good fucking thing he did because there's a sudden crack and creak and then she's falling and turning and elbows him in the face. Hard. Right by his eye.

As Fíadh shouts something from the collapsed grindstone, Faro's laid out on the ground, groaning in pain and holding his face.