Clerks - Gum in the Locks.
This not a slip up as it is a filming problem. At the beginning of clerks Dante opens the store and finds that some savages in that town jammed gum in the locks and the movie goes on as normal. Now it bothered me when I saw this because the only thing funny about it was that people kept asking Dante the same two questions " Why does it smell like shoe polish in here?" and " Are you open?"
I was wandering about this for a while because iv seen every Kevin Smith (Silent Bob) movie more then half a dozen times each and i could not figure it out, but now I got it. This was a project for him in collage, to make a full length film, and he filmed it in the same Quick stop that he has been working in for about a year. He asked his quick stop boss if he could film a low budget film while he was woking but the boss said no. So Kevin filmed most of the scenes at night other then a few (Berserker, Dental school, Jay and silent Bob, Funeral, etc) so in order to make day he would have to close the windows and turn on all the lights, and if you notice that when they come back from the funeral its dark and they can film all over the store without the night being shown through the glass door. So the people asking the questions were jest pro-longing the filming problem they had.