Factual error: Near the end, a copper pan is used to deflect a bullet. Copper is a soft metal - the bullet would have gone straight through. If you can pierce a copper pan with a knife (as i have seen done), then a bullet would have no issue.
Factual error: Near the end, no one in the hall realizes that a real diamond cannot be destroyed by a bullet. Also, even if it was a fake, it couldn't be blown to smithereens with a single gunshot.