How did Crow lose his arm?

[Ebony]

This is something I have wondered but there is no discussion on this that I could find. How did Crow lose his arm? You can see in the x-rays of him that his right (or is it left?) arm is missing from the elbow down. Nothing is ever mentioned in the game, as far as I could see, how he lost his arm.

Does anyone know?

[Mitch Rocks]

In the official Discord, Josh gave a longwinded joke explain without closure that effectively added up to just "There is not and may never be a canonical explanation for the arm."