Chapter Two: Vecna's Curse - S4-E2
Continuity mistake: After Mike kisses El on the forehead, Jonathan is in the back grabbing his glasses from his pocket. In one shot, he's grabbing them out, and then the next shot has them at waist-level.
Chapter Five: The Nina Project - S4-E5
Continuity mistake: The seat belt keeps appearing and reappearing on Nancy's shoulder as she's driving.
Chapter Seven: The Massacre at Hawkins Lab - S4-E7
Continuity mistake: Eddie is still wearing a denim vest he took off his body and threw at Steve a few seconds earlier. When the camera cuts away and back, the vest is gone again. (00:15:19)
Continuity mistake: Eleven makes the helicopter fall from the sky and blow up some army vehicles. Within a cut, it's much earlier in the day as the sun is right above her. Prior to this, it was lower in the sky and returns that way as she and the rest of the crew are driving away.
Answer: Technically Steve was never intended to die in Stranger Things. The Duffer brothers wrote a pilot script for a miniseries called Montauk that would eventually become Stranger Things. In that version of the story Steve is a more overtly villainous character and is killed by a monster. The Steve character was reworked once Stranger Things was created due to Joe Keery's more likeable approach to the character.
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