Factual error: In the scene in the glass elevator, when Mike Teavee wants to push a button, he presses the TV Room button. The elevator stops going down and immediately moves horizontally. The characters within the elevator are thrown against the wall from the sudden change. However, they are thrown against the wall that is in the direction the elevator is now moving, instead of the opposite wall as they should have been.
Trivia: In the scene with the young Willy Wonka eating a box of chocolates, he is writing down in a notebook a description of each chocolate he eats. When Roald Dahl was at boarding school there was a Cadbury's factory nearby that used the pupils as testers for their new chocolate, and they were asked to write down their comments in much the same way. This is mentioned in his book Boy.
Grandpa Joe: Mr. Wonka, I don't know if you remember me, but I used to work here in the factory.
Willy Wonka: Were you one of those despicable spies who everyday tried to steal my life's work and sell it to those parasitic copycat candy making cads?
Grandpa Joe: No, sir.
Willy Wonka: Then wonderful, welcome back.