The right way to "correct" your boss

In his post 5 easy ways to commit career suicide, Calvin Sun warns against contradicting the boss in public: "Suppose that your boss, while giving a presentation, makes a factual error. Should you jump in and correct the error immediately, secure in the knowledge that your boss will thank you for underlining the mistake in front of an entire room of people?"

Calvin says "Correcting your boss in public will hardly endear you to him. More likely, he will be upset at being made to look foolish..."

But what if the correct information is truly important? Calvin recommends approaching the boss during a break"... and quietly mention the mistake. A smart and gracious boss, upon resumption of the session, will identify the error, apologize and credit you with the correction."