Don Simpson was largely responsible for creating the critical General Hummel character. Simpson watched a 60 Minutes (1993) segment about the U.S. government's refusal to acknowledge soldiers who had died during covert overseas missions, and later read Colonel David H. Hackworth's memoirs which harshly criticized U.S. planning during the Vietnam War. He combined these elements into Hummel's character and, as Jonathan Hensleigh described, created "a really compelling villain: a soldier with a noble end, but, unfortunately, psychotic means."
While the film was shooting, Alcatraz was still open to the public, and many visitors watched the movie being shot. However, on December 15, 1995, the federal government, which owns Alcatraz, partially shut it down, due to stalled budget talks, and filming continued with no visitors present.
According to William Forsythe, when he was three weeks into shooting the movie, and they were about to shift locations for filming, Forsythe was mistaken for an extra, when he was getting a hot dog from the set's catering. Forsythe said the employee told him that extras weren't allowed food from craft services, and she summoned security, who subsequently said that he was part of the main cast. Forsythe said "I ate my hot dog, but I'm thinking two things: the fact that, after three weeks on the movie, I was being forbade a hot dog, and, 'I don't know what the hell they've got for the extras today. Trail mix, maybe?'".
In the scene in the interrogation room where FBI agent Stanley Goodspeed introduces himself to John Mason (Sir Sean Connery), John replies "But of course you are". This was exactly the same line he used when he met Plenty O'Toole in the casino scene in the Bond film Diamonds Are Forever (1971).
Arnold Schwarzenegger was offered the Mason role, but at the time the script was only eighty pages "with a lot of handwriting and scribbles, and it didn't seem fully baked." In a Reddit AMA, he stated he regrets not taking the role. Years later, however, he played a part as a convict with a mysterious past, in Escape Plan (2013).
There were tensions during shooting between Michael Bay and Walt Disney Studios executives, who were supervising the production. On the commentary track for the Criterion Collection DVD, Bay recalls a time when he was preparing to leave the set for a meeting with the executives and was approached by Sir Sean Connery in golfing attire. Connery, who also produced the film, asked Bay where he was going, and when Bay explained that he had a meeting with the executives, Connery asked if he could accompany him. Bay complied, and when Bay arrived in the conference room, the executives' jaws dropped when they saw Connery appear behind him. According to Bay, Connery then stood up for Bay, and insisted that he was doing a good job and should be left alone.
In 2016, the Chilcott report on Britain's involvement in toppling Saddam Hussein, noted that one Agent, who had falsified claims about observing weapons of mass destruction in Iraq, had based his description of them on the nerve gas missiles featured in this film.
Each morning and evening the cast and crew made their way across the bay to location by way of the Red & White Fleet, a charter tour service, whose boats also carry the 4,000 tourists a day who visit Alcatraz.
Goodspeed only swears twice in the film when he kills the last two villains. Throughout the rest of the film, his language is tame, saying words like "gosh" and "friggin", while other characters get the profanity laden lines.
At the beginning of the movie, General Hummel kisses his wife's gravestone, and leaves behind his Medal of Honor, the highest award in the armed forces of the U.S. It is bestowed on a member of the U.S. armed forces who distinguishes himself "conspicuously by gallantry and intrepidity, at the risk of his life above and beyond the call of duty, while engaged in an action against an enemy of the United States".
The guy who gets his car stolen by Sean Connery is the same guy who got his car stolen by Ed Harris in National Treasure: Book of Secrets (2007), another of Jerry Bruckheimer's movies which also starred Nicolas Cage and Ed Harris.
During the chase scene after Mason escapes from the hotel, he crashes through a truck delivering bottled water. In The Presidio (1988), Sir Sean Connery's character tracks a smuggling operation that involves the same type of truck.
In the scene in which Paxton demands to know from Womack who Mason is, Paxton utters, "Yeah, I know all the cloak and dagger stories." This line was a direct reference to William Forsythe's earlier film Cloak & Dagger (1984).
Pat Skipper plays an uncredited U.S. Navy Lieutenant Commander, working at the Pentagon in this film. He also played Bill Scully, Jr. in The X-Files (1993) who was Dana Scully's older brother. Bill Scully was also a Lieutenant Commander in the Navy, and also worked at the Pentagon.
The trivia items below may give away important plot points.
When Stanley and Carla are making love on the roof of their apartment, the Sir Elton John song "Rocket Man" is playing in the background. This is the same song that Stanley refers to later in the movie (at around one hour 55 minutes) when he kills Captain Darrow.
The scene in which FBI director Womack is thrown off the balcony, was filmed on location at the Fairmont Hotel in San Francisco. The filming led to numerous calls to the hotel by people who saw a man dangling from the balcony.
Aside from the obvious references to Sir Elton John's "Rocket Man", there is another, more subtle astronaut-themed reference: Major Baxter's first name is Tom, hence Major Tom, the ill-fated astronaut from David Bowie's "Space Oddity."