At one point, Cottonmouth calls Luke "Harlem's Captain America". Like Steve, during his hit on Crispus Attucks, Luke uses a car door as a ballistic shield.
When Misty's superiors inform her that Scarfe is under investigation by Internal Affairs, Lieutenant Perez says "We have a lot of eyes on us, Misty," which implies that the NYPD is cracking down hard on any suspected corruption within the ranks, in light of the number of cops found to have been in Wilson Fisk's pocket.
When Claire meets with her mother at the diner, she mentions that in light of The Hand's attack on Metro-General and the hospital's cover-up, and her own experiences with Matt Murdock and Luke Cage, she wants to exclusively help gifted people.
Blake Tower mentions Frank Castle's rampage during Diamondback's hostage crisis.
While they don't mention the Sokovia Accords or the events of Civil War due to season 1's timeline overlapping with Daredevil season 2, Misty's debate with Scarfe over the ethics of superheroism against government authority, sees Misty pointedly ask Scarfe, "Whose side are you on?", belying the very public discussion of measured oversight versus immediate results, that reaches an international level in the films.
In "Take It Personal", when talking about the Judas bullet, Diamondback tells Mariah that you don't need to kill God with one shot to sell a weapon; you just need to make Him bleed. This references Ivan Vanko's line about making God bleed from Iron Man 2.
Benjamin Donovan doesn't just work for Wilson Fisk, he also provides services to the Harlem crime syndicates.
During Method Man's song "Bulletproof Love," one set of lyrics goes "Lord, who to call when no one obeys the law? / And there ain't no Iron Man that can come and save us all?"
There is a conspicuous aversion in that there are no references to The Incredible Hulk. Despite taking place in Harlem and mentioning several other incidents involving superpowers farther from home, nobody brings up the fact that Hulk and the Abomination smashed up Harlem itself several years prior, even though we know it happened because one of the framed front pages in Karen Page's office is an old Ben Urich story about it.
When Luke is being sued for beating up Cockroach, Foggy asks Luke if hes ever considered wearing a mask to conceal his identity, like Matt did, to which Luke retorts, Im 63, black, and bulletproof.
Misty is getting adjusted to her life without her right arm.
The Biggie Smalls picture from Season 1 makes a reappearance after Mariah takes back the money Bushmaster stole from her, to emphasize exactly how much Mariah has become like Cottonmouth. And once again, when Luke has taken over Harlem's Paradise, with the camera once again pausing so that the crown lines up with Luke's head before he has it taken down.
In episode 9, Bushmaster's escape from a police van escorting him to jail is almost identical to Wilson Fisk's escape from custody at the end of Daredevil season 1. Right down to Bushmaster getting many of the same camera angles while telling an equally ominous story. The only real difference is that Fisk's escape was done by having a bunch of hired mercs ambush his convoy and kill the cops in the escort, while Bushmaster uses a grenade he smuggled into the van.
During a press conference, a reporter references a newspaper article by Karen Page.