The pineapple in the title refers to a hand grenade, as they look somewhat like a small pineapple.
Continuity: When Davy McCain is searching for the deceased Phillip Hedden's belongings in the shipping terminal, he finds them and the person to whom they are to be shipped to is listed as a Mrs. Louise Hedden in Iowa. Earlier it is stated that Hedden's belongings were being shipped to his sister in Iowa. If Louise Hedden is the sister, they would not have put the Mrs. in front of her name. If she was married, her last name would be something besides Hedden and if she was single, there would not be the Mrs. before her name.
Johnny Pop's character name is misspelled "Watchtman" in the end credits.
Fat Augie Strom appears to be loosely based on a real-life Chicago gangster named Joe Saltis whose territory included the Chicago stockyards.
Continuity: Six "small" crates of narcotics are mentioned, supposedly containing 150 kilograms of drugs. Only 150 kilograms equal 330 pounds, a bit more than Steve Ballard would be able to carry all by himself.
End Credits Goof: Lea Marmer is incorrectly listed as Leah Marmer.
(Goof) Ness' description of the fatalities in the hospital-- 2 patients and an intern-- don't match what we saw... unless one of the patients in the room happened to be an intern.
The gimmick of Ness allowing a suspect to escape in this episode in order to crack a case is a repeat of what he did in Season One's Doreen Maney Story.
The team of Dr. Victor Garr & Dr. Daniel E. Gifford had previously worked together in episode # 94 Bird in the Hand.
At the end of the episode, in the fight scene between Eliot Ness and Leo Stazak, the stunt double for actor Telly Savalas is obviously wearing a very fake-looking "bald" cap.
Joe Fuselli, a mob murder victim in this episode, has the same name as Keenan Wynn's character in the pilot episode of The Untouchables though they're obviously not the same person.
At the end of the episode, when a shot John Brecker falls over the rail and down the stairway, it's very obvious that it is a very fake-looking dummy.
Continuity: Sean Brannon is shown to be a poor auto mechanic who fixes other people's cars, but doesn't own a car of his own. But later it's revealed that there is a Brannon's Auto Repair, which should indicate that Sean and his family can't be that poor.
In the fight scene toward the end, it's obvious that a stunt double is subbing for the Bayless character as he doesn't look anything like actor Dan Dailey.
Edward Asner is mistakenly billed as Edward Asher in the ending credits.
Season Four would feature some weird names for the baddies due to the show eliminating all Italian surnames of gangsters. This episode marks the first of the weird ones with Vince "the Moor" Tunis.
The meet-- in front of St. Brandon's church in Roselyn-- takes place at 6:00 a.m. But it's obvious from the shadows that the sun is directly overhead, so this scene was filmed around noon.
The lead protagonist in this episode, Harry Gordon, has the same name as the show's set decorator.
Walter Winchell said the immigrants had come 6,000 miles. Since it's only 4,058 miles from Bremen, Germany, to Chippewa Lake, the immigrants must have taken some really roundabout detour through Canada.
Timeline Goof: The narration states that on February 16, 1929, Al Capone flew straight to Miami, and left Frank Nitti in charge of the Chicago operation. In actuality, Capone went to Miami prior to The Saint Valentine's Day Massacre. Nitti was in St. Louis, not Chicago, on February 16, 1929, getting married in a civil ceremony to second wife Anna Theresa Rango.