Oliver mentions calling Roy Arsenal which is his actual comic book alias. He made his debut as the Green Arrow's sidekick in Adventure Comics #250 in July 1958. He was originally known as Speedy and he was a ward of Oliver Queen with a similar relationship to that of Bruce Wayne and Dick Grayson.
In the comics Ted Grant is the superhero Wildcat; a member of the Justice Society of America, the Justice League, and trains several other powerless heroes. He is also the one who trained Dinah Lance the second Black Canary.
This episode establishes that Roy killed a cop instead of two cops which is what is shown in season 2.
Former Wildcat sidekick Isaac Stanzler was named after the director of This Is Your Sword (2015), Wendey Stanzler.