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: The scene you are referring to is a dream sequence. In dreams everything is different and how they change throughout the movie is no mistake.
SAZOO1975