Aluminum Christmas Trees: When Cherry Ganz falls to his death at the end, he lands in the back of delivery truck loaded with 10-gallon spring water bottles that shatter on impact. Comments lefts on IMDb and other movie sites suggest modern viewers are often shocked to learn there was a time when spring water jugs were actually made out of glass.
Complete Monster: Albert Ganz is a viciously homicidal criminal who loves nothing but money and killing cops. In the movie's beginning he escapes from prison with the help of his henchman Billy Bear, killing some guards in the process. He kidnaps the girlfriend of his former partner Luther in order to force him to give him some hidden money from a former robbery, threatening to “put holes in her you never even thought of” if he should fail. During a shootout with the first two cops to track him down, Ganz kills one of them and injures the remaining one. He takes a woman hostage and orders Cates, who was backing up the other cops, to hand him his own gun. Once Cates obliges, Ganz uses the gun to kill the wounded cop and then tries to kill Cates as well. Even after Luther brings him the money Ganz kills him for having asked his girlfriend if she's all right (he says "I told you I wouldn't hurt her"). In the final showdown, he uses his ex-accomplice Reggie as a Human Shield, clearly willing to kill him along with Cates, just for personal satisfaction.
Fanon Discontinuity: Some fans ignore Kehoe being the Iceman in the sequel, liking him better as a heroic character and feeling that it causes some continuity issues.
Genre Turning Point: This movie more or less invented the buddy cop/mismatched partners plot that has become become prevalent in Hollywood movies today. Director Walter Hill would also revisit the genre with Red Heat, this film's sequel Another 48 Hrs. and Bullet to the Head.
They Wasted a Perfectly Good Character: Many fans think Luther had some good tritagonist potential given how he has spent years safeguarding the secret of Reggie's money without ever trying to steal it for himself and his conversation with his girlfriend implies he is trying to make an honest living despite its difficulties. His navigating his role of being forced to serve Ganz while being loyal to Reggie and seeking to build a new life had a lot of potential. Instead, he is a relatively minor character who is treated and viewed as a cowardly The Friend Nobody Likes.
Jack says a lot of racist things, even outright calling Reggie the N word. While Jack's an antihero and does eventually acknowledge that he was wrong to do so, it's extremely unlikely that a character could do that in a modern film and be anything other than a villain.
As with most of Eddie Murphy's roles in The '80s, Reggie drops a lot of homophobic slurs for a character the audience is supposed to sympathise with. Moreover, unlike with Jack and his racist language, Reggie doesn't get called out for doing so and never apologizes.
The Woobie: Luther, when you tally up everything that happens to him. His girlfriend Rosalie (who he seems to deeply care about) is held hostage by the Ax-Crazy Ganz to make him get the money, he gets beaten up by Jack and Reggie, accused of being a traitor by his friend Reggie (due to lacking the context), put through a cat and mouse game all over town for most of the 48 hours (one of which ruins a public exchange where Rosalie was about to be released), and then gets shot right when it looked like things were over for him.
