Interesting POV. In Eric Jager's book upon which the film is based Marguerite's only chance to obtain justice is by way of Jean fighting Le Gris. Le Gris planned the assault too well, choosing the one day Marguerite is alone in castle de Carrouges. Hence I don't understand her riposte to Jean, seen in trailers, that he is risking her life for his own selfish reasons, rather than risking his on her behalf.
I'm not enough of a scholar of the period to know how accurate Jager's account might be. And certainly Jean de Carrouges is no dream husband. He was certainly more concerned with his own honor besmirched than the outrage visited upon Marguerite. Furthermore, he pregnancy complicates matters: was the baby Jean's or Le Gris's?
Still, if Jager is on point, then Scott's version isn't history. Marguerite didn't fancy being burned at the stake if Jean happened to have a bad day, but she did proceed with the accusation, leaving him little choice but to take up arms on her (& his) behalf.
The mullet, however... I guess that tells us all we need know about Scott & Damon's Jean de Carrouges.