James Arness's limp, the result of a war injury, is very pronounced in the scene where he walks with Coltrane on the latter's ranch. It prevented him from walking, or even riding, for long periods of time.
The title "widowmaker" refers to any person, animal, or machine that has a history of killing the men near him, her or it. In more modern times, certain vehicles, aircraft and weaponry have been called widowmakers. It can also refer to loose overhead debris in the forestry industry or a type of heart condition.
The cast is loaded with members of show biz families. James Arness is the brother of Peter Graves; Steve Forrest's brother is Dana Andrews; Buck Taylor is the son of Dub Taylor; Milburn Stone's uncle was Broadway comedian Fred Stone; and Barra Grant is the daughter of Bess Myerson.
Dad Goodpaster says one of the four men who could have taken the three gunmen at the beginning was named Jobson, but he was in jail. During the previous season Alex Cord played a fast gun named Jobson in an episode called "The Sodbusters". It's likely Goodpaster is referring to the character in the earlier show.