Mickey Rooney was surprised by the fast pace of shooting and once asked David Janssen how he could "stand all this noise." Janssen replied "what noise?" because he was used to the frenetic pace.
This is a re-teaming of David Janssen and Mickey Rooney. Five years prior to this, they also starred together in King of the Roaring 20's: The Story of Arnold Rothstein (1961). Much earlier, when Janssen was under contract at Universal-International, he had a bit part in Rooney's film Francis in the Haunted House (1956).
Nita Talbot and William Conrad both guest-starred in the series Barnaby Jones (1973), but in different episodes. They do share credit and scenes in a couple of movies: The Cool Ones (1967) and Turnover Smith (1980).
This is the second of three appearances Phillip Pine makes in the series, each time playing a different character. The other two appearances occur in Brass Ring (1965) and Nobody Loses All the Time (1966).
The Hotel Clinton makes another appearance: Throughout the series it is used as the name of whatever fleabag Kimble (or whoever) is holed up in. In this case, it's the hotel Charlie, played by Mickey Rooney, holes up in.