Other mistake: In the beginning when Kali and her gang are running from the police in Pittsburgh and she "collapses" the tunnel, her 008 tattoo is shown this way so we can read it as such, but it should in fact be read 800 to be the correct way. (00:03:15)
Factual error: During the police pursuit in Pittsburgh, the officers are wearing shoulder speaker/microphone handsets. The models are the Motorola Saber radio, which wasn't introduced until 1989, while the season takes place in 1984.
Revealing mistake: When Bob and Joyce have lunch, Bob pops open a can of soda (which is period appropriate). The scene cuts to Joyce, then back to Bob. It is clear from how he is holding the can, and how he pretends to drink from it, that his newly opened soda is actually empty.
Other mistake: When Will is in the hospital, talking about being frozen, they cut to the hallway and the lights on the suspended ceiling are 2' x 4' LED lights that didn't come out until the 2000s.
Suggested correction: There is nothing to indicate they are LED lights. They appear to be translucent panels illuminated by fluorescent lights.
Chapter Two: Trick or Treat, Freak - S2-E2
Continuity mistake: In episode 1, during Will's appointment discussing his episode, the doctor said "how did you feel, when you saw the storm?" Will then replies "Frozen." Doctor says "Heart racing?" Will: "Just frozen." Doctor: "Frozen? Cold frozen? Frozen to the touch?" In this episode When the doctor watches the tape of his conversation with Will from the previous episode the dialogue is different. On the tape, after Will says "frozen" the doctor then says "actually frozen cold?" Which he didn't say in the previous episode. And his actual lines from the first episode are missing. (00:25:15)
Chapter Two: Trick or Treat, Freak - S2-E2
Continuity mistake: As Hopper and El sit down to breakfast after she has surprised him as a ghost, he tells her he will bring candy home etc. When the camera is on Hopper, El is leaning on the table, but when the camera is facing her, she is leaning back.
Chapter Three: The Pollywog - S2-E3
Factual error: The cordless drill used to fix door bolts in the new cabin is modern, not from the 80s.
Chapter Three: The Pollywog - S2-E3
Continuity mistake: When Dart is found in the bathroom cubicle by Will, he drops his walkie talkie when he runs away, but shortly after when his friends arrive the walkie talkie is gone.
Continuity mistake: When Mike and Will are discussing Will's visions near the start of the episode, the sweat stain on the front of Will's shirt disappears and reappears between shots. (00:01:30)
Chapter Eight: The Mind Flayer - S2-E8
Factual error: When El arrives, Hopper rifle has a picatinny rail, inaccurate for the time period.
Chapter Eight: The Mind Flayer - S2-E8
Factual error: Joyce asks Will if he remembers when he was 8 and she bought him that giant box of crayons for his birthday - the 120 pack. Will is 13 in the show, so when he was 8, it was 1979. There were only 78 colors available in 1979 and the 120 crayons box was not available until 1998, almost 20 years later.
Chapter Nine: The Gate - S2-E9
Factual error: The military convoy has Desert Tan HMMWVs (Humvees). The Army didn't take delivery of the first ones until 1985 and they certainly were not painted Desert Tan until 1991 in the Gulf War.
