You could argue that the Blockbuster employee was merely looking out for Peterborough Mayor Keith Sharp's best interests—saving him 90 precious minutes!—but Sharp was not happy about being banned from renting the movie.
As it turns out, the befuddled Blockbuster employee saw the health and safety warning associated with renting out 3D glasses—because of hygiene, you see—and refused to rent him the actual movie, instead. While a large percentage of the population can't stomach 3D films, suffering from headaches and dizziness, it's certainly not a reason for Blockbuster to refuse to rent movies stocked on their shelves.
Humorously, Sharp, the Mayor of Peterborough, England, has actually been a health and safety adviser for the past 14 years—though I imagine most of you are chuckling over the thought of anyone still holding a Blockbuster membership, let alone someone who can afford to buy a 3DTV. [Metro via TechRadar]