Stranger Things: 15 Stupid Mistakes You Completely Missed
4. M&Ms
The third season may have been the most divisive in terms of fan response, but it also wan't immune to those uncharacteristically anachronistic errors.
This one came when Mike and Eleven were in the Hawkins Memorial Hospital waiting room with Will, Lucas and Max right before the mini-Mind Flayer attacked Nancy and Jonathan. In one of the few moments of quiet between the most important couple on the show, Mike tried to make peace with El after Hopper and Max unwittingly tried to destroy their relationship. That peace came in the form of M&Ms that he obtained from the hospital vending machine.
But those M&Ms must have been pretty special because, in a blink-and-you'll-miss-it moment, a red one could be seen among the bunch he poured into El's hand. Why is that suspicious, you ask? Well, only because the red M&M ceased to exist after the 1970s after the red dye was ruled as being unsafe to eat. They were eventually reinstated in 1987... two years after the year that Season 3 is set in.