Trivia: When Deadpool autographs the cereal box he signs it Ryan Reynolds.
Trivia: Young Cyclops, Beast, Storm, Quicksilver, Night Crawler and Professor Xavier from the First generation timeline (ie. X-Men: First Class onwards) make a very brief appearance as Wade complains there aren't any X-Men in the mansion. They shut the door so he doesn't see them.
Trivia: On the scrolling text during the news broadcast it says "Notorious bank robbers Westervelt and Ghizas arrested Sunday evening after high speed chase." Dirk Westervelt was the film editor for "Deadpool 2." He also was an editor for "Logan." Nick Ghizas was the visual effects manager for "Deadpool 2." He was also a visual effects artist for the TV show "Agents of S.H.I.E.L.D." Westervelt was also an editor for the film "Notorious" and "Faster."
Trivia: When Deadpool and Cable are fighting on the truck, Deadpool at one point refers to him as "One eyed Willie." This is a reference to the pirate from The Goonies which co-starred Josh Brolin, who plays Cable.
Trivia: The two rednecks sitting on the back of the pick up truck when Cable arrives are played by Alan Tudyk and Matt Damon, whose makeup took 4 hours to apply.
Trivia: During the end fight a Wilhelm scream can be heard.
Trivia: Deadpool's inmate number in the Icebox is 24601. This is the same number used by other characters such as Sideshow Bob from The Simpsons and Eric Cartman from South Park. It is also the same number of Jean Valjean in the film version of Les Miserables where Hugh Jackman played the role.
Trivia: When Deadpool and Cable are fighting on the truck, Deadpool slices a bullet in half. This is a similar scene to "X-Men Origins: Wolverine" where Wade Wilson does the exact same thing.
Trivia: Tim Miller, who directed the original film, left production early on and was replaced by "John Wick" co-directer David Leitch. Reportedly, Miller and star Ryan Reynolds had vastly different visions for the sequel, and Miller was already in early prep for the next "Terminator" film, so the two amicably agreed that Miller should step away and allow a new director to take over.
Trivia: Brad Pitt makes a quick cameo as the Vanisher and Hugh Jackman appears at the end as Wolverine, albeit in old footage from X-Men Origins: Wolverine.
Trivia: At the start of the scene where Deadpool and Weasel are recruiting the X-Force, they are looking at photographs of the applicants. The first photo shown is of Ruth Bader Ginsburg, an Associate Justice of the Supreme Court. A closer look at the photo will show that her superhero name is Notorious R.B.G. (00:53:55)
Trivia: Director David Leitch has a cameo as "Ground Chuck Mutant", one of the mutant prisoners taken on a truck to a new location.
Trivia: When Deadpool retrieves the cocaine from Blind Al's apartment, the bags of coke are sitting next to another object labeled "The Cure for Blindness." This is a bit of a callback to the first film, in which Deadpool facetiously told Al that he had cocaine stashed somewhere in the apartment next to "the cure for blindness." Evidently, he literally did have a cure for blindness.
Trivia: It was revealed after the film was released that Ryan Reynolds himself was the voice of Juggernaut, in addition to portraying the facial motion-capturing work for the digital model. They simply deepened his voice in post-production. In the credits, the voice of Juggernaut is listed as "himself".
Trivia: Scrolling text on a news program in the film jokingly states that Christopher Plummer refused a role in the film. This is a dual reference to Plummer replacing Kevin Spacey in the film "All the Money in the World" after Spacey was accused of sexual misconduct, as well as TJ Miller also being accused of sexual misconduct prior to this film's release, which led to some people demanding that Miller be removed from the final film.
Trivia: Spoiler alert! Zeitgeist has the number 116 tattooed on his arm. This is a reference to the issue number of the comic in which he dies.
Answer: His change of heart came from Deadpool's sacrifice. In the second timeline, Cable saves Deadpool, but Deadpool had no way of knowing. Firefist still has a change of heart because Deadpool was willing to sacrifice himself, even though he was ultimately saved by someone else.
Now, I can accept that in theory, except that Russell repeatedly saw Deadpool putting his ass on the line to rescue Russell. I mean, Russell knew from the very beginning that Deadpool could have killed him (but chose not to) and took some severe ass-beatings on Russell's behalf. Russell was really, really hard-boiled, and I'm not seeing that Deadpool almost getting killed as enough impetus to change Russell's heart. It seems (to me, anyway) it was Deadpool's actual death that changed Russell, such that a mere deflected bullet would not have the same effect.
Charles Austin Miller
Deadpool often mentioned "lazy writing" and Russell having such a change of heart might be an example of it.
Erik M.
Deadpool saving Russell in the film is what made Russell think that they were friends. When Deadpool tells Russell that they aren't friends, he remains hostile toward Deadpool, not believing him when he later admits to caring for Russell. At this point Russell is too far gone and will kill. However, it's only when Deadpool takes a bullet for Russell, fully intending to die in both timelines, that Russell sees that Deadpool really does care about him, and would have died to save him.