Continuity mistake: At the end of the town collapse, a sincerely drunk Ben dives head-on into a tub where a lady (in her underclothes?) is just enjoying a bath. Propelled by Ben's momentum the tub with both passengers slides down the slippery planks and splashes into the river, while Ben rearranges himself into a comfortable sitting position between shots. If I wasn't completely mistaken also the lady changes her outfit, since the embroidery is missing when they float along. (02:23:35)
Continuity mistake: When Lee Marvin hits Clint Eastwood and interrogates him about riding the same horse with Elizabeth, Marvin's chin strap alternates begins the scene tucked tightly under his chin, then is resting against the front of his face, then tucked under his chin again, yet he never touches it with his hands.