During the scene when Donner speaks with Paladin in his suite, Donner's monocle is worn at his right eye. At the end, when Paladin walks to the door to show him out, Donner is suddenly wearing it at his left eye. At the very end, the camera show him from a back angle, and he clearly does not have the monocle at his left eye.
Donner: I, uh, hope you didn't allow my young friend to talk you into anything foolish.
Paladin: Well, I hope not, too.
Hey Girl: Your recklessness leads you to riposte before you parry, Mr. Paladin.
Paladin: Is that so?
Franz: Nonsense! If he would only practice more, he would make a superb swordsman.
Paladin: Well, in my profession, swords are a little bit out of style; thank you, Hey Girl.
Fencing partner: Who is that young man?
Paladin: An Austrian tourist. And perhaps Pope was right. "He's armed without who's innocent within." Perhaps.
Paladin: Franz, you are a very nice young man. Go home. Go home to your castle and lock the door, and practice "dip the knee" to your princely heart's content, but don't stay here. Don't stay here unless you're prepared to sacrifice your illusions and possibly even your life.
Franz: I will double your fee.
Paladin: It's not a question of money.
Franz: Then what?
Paladin: It's an old aversion to helping people make fools of themselves.
Donner: Now, Franz is inclined to be a trifle--impressionable. He thinks of you as a colorful and attractive figure, which of course you are. But not, perhaps, just the kind of man one would expect to find in a royal entourage. Do you follow me?
Paladin: I believe so. Gunfighters are not the thing in court circles this year.
Donner: So droll! It's marvelous!
Franz: I don't understand, Herr Paladin. Your refusal seemed so positive. What made you change your mind?
Paladin: Well, let's just call it a feeling that somebody ought to be there to catch you when you fall. That, plus a certain amount of persuasion.
Paladin refers to Alexander Pope (1688-1744)
The line is actually "He's armed without that's innocent within", and comes from Pope's Imitations of Horace (1733-1738)