You see, it's generally considered desirable in the publishing business to take a certain liberty when you're depicting the cover scene. It is for reasons involving the marketplace, et cetera.
12 seconds sound clip from the Unforgiven movie soundboard.
You can hear this line at 00:54:26.700 in the Blu-ray version of the movie.
Quote context
[...]
- Boy, they look like real hard cases, Bob.
- Did you kill all seven of 'em, dead? Or did you just wing some of 'em?
- Now, that is you there, Bob, on the cover. The Duck of Death? It's the Duke. Duke of Death.
- You always were a hell in Jesus with a pistol, but seven of 'em? Boy.
- And you protectin' that woman and all that. How the hell do you do that?
- Well, from what I read in this here book, the writing's not that much different than the picture.
- You mean like the Duck himself, I guess.
- You have insulted the honor of this beautiful woman, Corcoran, said the Duck. You must apologize.
[...]