The shot of Mannix skiing down the slope would subsequently be used in the show's opening credits starting in season six.
The last television appearance of Patricia Medina. Two years later her last movie, The Timber Tramps (1973), was released. The film also featured her husband, Joseph Cotten.
This episode must have been filmed during season four in the winter of 1970-71, as it was filmed during winter time. Any show at the beginning of a season (like this one) would have been filmed during the summertime, which this one was clearly not.