When Evelyn Sharp says: "what kind of vigilante wears a hockey mask anyway?" Oliver Queen responds: "I think it's cool". Stephen Amell who plays Oliver Queen/The Green Arrow played the vigilante Casey Jones in the Teenage Mutant Ninja Turtles: Out of The Shadows earlier this year, who is famous for wielding a hockey stick and hockey mask.
Stephen Amell has a long-standing history with guest star Cody Runnels. The two coordinating in several charity fundraisers and had an ongoing feud in WWE, where Rhodes played the character "Stardust." This culiminated in a high profile tag team match at The pay per view Summerslam in which Amell was victorious.
In the factory fight, Wild Dog fights Derek Sampson on a catwalk and then drops him into a chemical vat... much like the way that Batman fought the Red Hood, and dropped him into a vat of chemicals (which created the Joker)...a true homage.
The street drug featured in this episode is called "Stardust". Guest star Cody Runnels portrayed the wrestler "Stardust" in WWE.
Talking about Wild Dog's Hockey mask,Oliver says, "Its cool". Stephen Amell played Casey Jones in Teenage Mutant Ninja Turtles: Out of the Shadows (2016), a vigilante who also wears a Hockey Mask.