Factual error: When Glen and Nancy are talking on the bridge, you can see huge palm trees in the background. Though this was filmed in California (hence visible palm trees at the cemetery), the fictional Springwood is supposed to be in Ohio - they show the location of Springwood on a map at the start of 'Freddy's Dead, the Final Nightmare', and there's no other conflicting in-universe location given within the series. So it's established as Ohio, but there are no palm trees in Ohio. Other California "hints" add to the mistake, such as CA license plates, etc. (00:01:00 - 00:43:22)
Factual error: The moment Nancy's digital watch hits zero, her bedside clock rings waking her up. You cannot set an old, mechanical style alarm clock to go off with anything like that level of accuracy. (00:32:00 - 00:33:18)
Answer: She was not awake. People scream, get out of bed and walk around, and even have conversations while sleeping.