Are you sure that pic is from the duel itself Ingwar?
De Carrouges might well have worn his English campaign armour again since he would be comfortable and familiar with it, but the background is more of a castle setting as opposed to the open dueling field and wooden grandstands we saw earlier.
According to the book Le Gris will have a suit of full plate armour (very, very rare at the time) at the duel while de Carrouges will wear the lighter plate and chainmail combo (as shown in the photos)
While Damon's armour appears to be very period authentic, his horse's armour looks to be more early Renaissance era. Not that I mind though, as long as it looks cool I'm happy.
