After the scene of Lee Marvin holding Donna Reed against the wall, she was so terrified by him that she did not let him come near her on and off the set.
Although Roy Huggins was blacklisted (for being a former member of the Communist party), he still was able to write and direct "Hangman's Knot" under his own name. Producers Randolph Scott & Harry Joe Brown brought him in to direct it for Columbia Pictures. It was a financial success.
When Lee Marvin (Bainter) shoots Glenn Langan (Petersen) in the back, at around the 12-minute mark, it is one of the first uses of a blood squib in a Western. It predates other claimed 'firsts' by several years.