At the end, Lily is seen petting Olivia, her one-eyed cat. The cat is missing it's right eye. In Glued (2004), when Lily introduces ADA Kite to Olivia, the cat is missing it's left eye. The CGI dept removed the wrong eye.
At the end of the show when the shooting was being remembered, you can see May getting up twice. Once when the car was pulling away in an aerial shot and then again in a side shot of the scene.
In the opening scene, the teenagers are in the car listening to Bruce Springsteen's song "No Surrender." The date shown on the screen is June 6, 1980. "No Surrender" is from Springsteen's album "Born In The USA," which was not released until 1984.