Apparently this episode took place in April 1972, two months after the episode was broadcast. The calendar in the backroom of Lou's bar is showing the month of April and the dates are consistent with the year 1972.
Actors Fred Beir and Joan Hotchkis (in the recurring role of Oscar's doctor girlfriend Nancy) appeared in The Odd Couple episode "Felix' Wife's Boyfriend" earlier this season (1971-72). Beir played Nancy's brother.
Jesse Wayne doubled Eddie Firestone when he's shot climbing a high alley fence, falls from the top, hits a dumpster, bounces to the cement.