Monsters, Inc. continuity

When Mike first tries to put Boo back through the wrong door the clock on the Scare Floor shows 8.50 AM. Boo runs off and Randall intercepts Mike and Sulley. Sulley goes after Boo, but Mike is chased by Randal. The chase is very short but when Randall catches Mike it is 11.55.

Some poindexter at moviemistakes.com has tried to rationalize this, but you don't watch as much Monsters, Inc as I have over the last few days without spotting a genuine mistake.