Take a close look at the flag behind the court-martial panel. It’s a little bit out of date. Submitted by Earl Poulsen, 10/6/04.
+ The official flag of the United States, prior to July 4th, 1959 had 48 stars. Between July 4th, 1959 and July 3rd, 1960, the flag had 49 stars. The flag did not have 50 stars until July 4th, 1960. This was because of an executive order by President Eisenhower. In addition, all existing supplies of 48- or 49-star flags were to be used until unserviceable. So, it is entirely plausible that a 48-star flag could be displayed. It could not have been a 50-star flag because the episode was filmed before this flag was available. Read more here. Submitted by Christopher Stout, 2/21/2006.

In the scene at the dock after the murder, small signs identify two submarines as the USS Swordfish and the USS Moray. In reality SS-276 was the USS Sawfish. The hull number for the Moray is hard to spot but it looks like 301, 801 being too large. The SS-301 was actually the USS Roncador. The real USS Moray had hull number SS-300. The Sawfish and Roncador were based at San Pedro and used for training at the time the episode was probably filmed. Submitted by Steve Fox, 10/8/2004.

In the initial scene between Jim and Jerry, one can see behind them a destroyer. This was the USS Walke (DD-723), in commission from 1944-1970. cgraul 6.6.12
+ Another ship visible in the background is the destroyer tender, USS Frontier (AD-25) which saw duty from 1946-1968. Submitted by Steve Fox, 4/11/2020.
+ Another ship is visible behind Chief Scott, it's the USS Eversole (DD-789) which saw duty from 1946-1973. Submitted by Steve Fox, 2/5/2023.

Perry practices before a Naval court martial board in this episode. Earlier, in episode #43, TCOT Sardonic Sergeant, Perry had practiced before an Army court martial. Submitted by PaulDrake 33, 20 May 2009.
+And in "Misguided Missile"/E120, Perry practices before an AIR FORCE court martial. Mike Bedard 8.4.16

The prosecutor in this episode (Commander Driscoll) is played by Edward Platt, best known for playing the boss of Maxwell Smart in the 60s sitcom, Get Smart. Submitted by PaulDrake 33, 20 May 2009.

This episode marks the first appearance of Mort Mills as (Chief) Barry Scott in the Perry Mason series. Mort will go on to appear in 7 more episodes portraying police Sergeant Landro (sometimes credited with a first name of Ben). Submitted by DaveT, 29 May 2012.

Uncredited Actors: Don Anderson appears here as one of the two shore patrolmen who have seaman Chapman in custody on the sub’s deck and escort him down the gangway to shore. Read more about Anderson and other uncredited actors. Submitted by FredK 7, October 2010; updated by gracep, 10/7/2010.

Sightings: Distinguished Gentleman #1 appears as a bartender sporting a tropical print. Read about him and other favorite frequent faces on the Who Is That? page. Submitted by gracep, 10/10/10.

Star Trek Alert: Richard Geary, who appeared in 13 Perry episodes, went on to join the Star Trek universe, appearing in six original series episodes, as a stunt double, an alien, and as a red shirt who inevitably got killed. Submitted by MyFavoritePolarBear, 1/18/23.

CARS. (1) 1957 Chevrolet 150 4-Door Sedan, Cmdr Page, US Navy vehicle# 92-05992.

Background Cars at ALPHA ELECTRONICS as Cmdr Page arrives in Car(1) early in episode:

The Navy Ambulance, Car (2), was built by Superior Coach Co on a stretched Pontiac chassis using Bonneville body & trim parts. The hulk of one of these '58 Superior-Pontiac Navy Ambs is reported to be sitting in the Nevada desert (here, second photo below highlighted text). See Ep#127 for more of these "Professional Cars". Added by Gary Woloski 6/10/12.

Costumes: In this episode, Perry wears his usual button-down collar near the submarine dock, in the Alpha office, in the jail, and in court. But when Perry is in his office at 7:50 and later at 26:50, he wears his rounded club collar with collar bar (not quite so tight as in TCOT Nimble Nephew). Perhaps the two office scenes, which occur on different days, were filmed in close succession. Submitted by 10yearoldfan, 22 Sept 2012.
+ Scenes filmed in one set were generally filmed together to avoid setting the lighting, etc. more than once for the same set. Submitted by Wiseguy70005, 2/19/14.

Anomaly: Perry refers to the optometrist's office address as being on "Michigan Boulevard," Chicago; but this grand thoroughfare has been called "Michigan Avenue" ever since the Chicago fire of 1871. Submitted by 10yearoldfan, 22 Sept 2012.

Cold case / old case: Perry also solved the murder of Dolores Chapman killed three weeks earlier. Submitted by H. Mason 9/27/14

According to Wikipedia, director/associate producer Arthur Marks served in the US Navy during the Korean War...MikeM. 8/8/2016

This is the only PM appearance for Ann Robinson, who was born and raised in Hollywood CA...MikeM. 11/14/2016