Factual error: Cameron tries to stop Ferris from borrowing his father's red sports car, explaining that it's an extremely rare and valuable '61 Ferrari 250 GT California. But the car itself is not a real Ferrari. It was manufactured by Modena Design and Development of El Cajon, California, and is a "Modena GT250" which strongly resembles the 1961 Ferrari 250 GT California Spyder. Since the film makers were throwing the car out of a window, using a real Ferrari was 'cost-prohibitive'. Comparing the real Ferrari to the Modena, differences include the Modena's sharper body crease above the grille, the more steeply angled headlamp covers, higher-mounted emblem and counter-sunk hood scoop.
Factual error: The odometer only goes up by 10 miles between the time Cameron freaks out and when they're back in the garage, but when Cameron freaks out they're at a famous Chicago lighthouse that is 1/2 hour outside the city, more than 10 miles, so the odometer should have increased by a larger distance.
Factual error: When Cameron melts down and starts kicking the 1961 Ferrari 250 GT California Spyder, he dents the front bumper. There is no way a human being could dent a pressed-steel, chromium-plated bumper by kicking it.
Answer: Sloane knew it was a hoax. Ferris would not have done something like that without her knowing. Rooney pretty much had figured it out, but could never prove anything. Once he was discovered inside the Bueller house (illegally) by Ferris' sister, anything he did know he would have to keep to himself.
raywest ★
Sloane starts to put her jacket on the moment that she sees the school nurse walk into the classroom, suggesting that Sloane already knew she would be called out, and she smiles to her classmates.