u/HebrewHamm3r

I've been thinking about this since rewatching 1917: what if Col. Mackenzie had read the letter and simply said "Yeah, well you're probably a German spy trying to stop me in my moment of triumph" and gone ahead with the attack that he was ordered by General Erinmore to stop? What happens next?

Yes, obviously the Devons would have been wiped out, but what specifically would happen to Mackenzie in this situation?