The paper found that Irvine lied about being a knight in England; lied about the nature of his college degree; was not really a full-fledged "White House chef;" has bragged about a "Five Star Diamond Award" that is basically available to any asshole with a credit card; and owes thousands of dollars to people who worked with him on his unopened restaurants. He also may have acted like a jerk while out in St. Petersburg restaurants, possibly the biggest sin of all for a food industry guy. They do acknowledge that he's a good cook, though.
This video repeats a lot of the assertions about his experience; might not get to hear those again. If the cooking thing doesn't work out for him, he'd make a good contestant on "American Gladiators."