Other mistake: When Chevy chase is being filmed cheating on the exam, all the video cameras are on the sidewalls near the roof. But later when they view the footage, the last shot of Chevy copying the answers is from the floor level where no camera was seen in any previous shots. Also what was a floor level camera going to film anyway...everyone's feet?
Other mistake: When the container with Millbarge and Fitz-Hume in it falls, it's at a steady rate. When it comes into camera range on the ground, it drops slowly for the first second, then speeds up to crush the building.
Answer: Dan Akroyd was giving Chevy Chase the answers to the test, KGB was one of them.
JamesP