Likely the same logic that went into a lot of Western Christian belief about chivalry and witch-hunting - that God (or whatever Assyrian equivalent in this case

Likely the same logic that went into a lot of Western Christian belief about chivalry and witch-hunting - that God (or whatever Assyrian equivalent in this case) would judge innocence or guilt through the laws of nature. You have to remember that "logic" presupposed magical thinking and religion at the time.