The first person to tackle the terrorist on the train was a Frenchman. He later turned down the Légion d'honneur and asked to remain anonymous because he feared reprisals from other Islamists living in France.
Clint Eastwood was attached to direct The Ballad of Richard Jewell (????) since 2014 but dropped out in 2016 to do Impossible Odds (????) as his next directorial project after finishing Sully (2016) but the project wasn't ready yet & needed more time in development. So, Eastwood needed another project to take on & decided to sign on to helm this project as his next directorial film.
This film marks the first time that Clint Eastwood and DP Tom Stern used Zeiss Master Anamorphic lenses, which have the least anamorphic distortion. Their previous anamorphic shot movies were Filmed in Panavision.
Many of the professional actors in this film are better known as sitcom stars: Tony Hale and Judy Greer were both in Arrested Development, Jenna Fischer in The Office, Thomas Lennon in Reno 911!, and Jaleel White in Family Matters.
The trivia item below may give away important plot points.
Roughly eight weeks after the Thalys train attack, Spencer Stone was stabbed in the back several times by James Tran, outside a downtown Sacramento night club. Stone suffered wounds to his lungs, liver and heart, and he had to undergo emergency open heart surgery. In 2017, Tran was found guilty of attempted murder, causing great bodily injury and the use of a deadly weapon and was sentenced to nine years. Stone was quoted in the Sacramento Bee newspaper, saying, "At the end of the day, I forgive the guy. We all make stupid decisions, some dumber than others. I hope he learns from it."