Sad and ironic
That Jimmy Stewart and Anthony Mann made so many good pictures together and had such a disagreement over this film that they never even spoke again. I've even heard that Stewart refused to discuss Mann or the films they had made together following this.
Ironically, Stewart's friend Henry Fonda took what would have been Stewart's role in Mann's next film, "The Tin Star", (fortunately Jimmy didn't stop talking to Hank). It's doubly ironic because Fonda had had a disagreement with John Ford, who had made many great films with Fonda, during the making of Mr. Roberts a couple of eyars before and never made another film with him. Ford hired Stewart for "Two Rode Together", (1960). One wonders if Fonda might have played that role had there been no disagreement.
One wonders how people who have collaborated so successfully so many times can allow such things to happen.