Two questions on California wage-and-hour law

Q. "Here are two wage-and-hour scenarios that I have been told are the law in California, yet I do not see the 'rule' that distinguishes them. Please explain it to me: (1) An exempt employee with two hours of vacation time, takes off a full eight-hour day for personal leave. This employee must be paid only for his two hours of vacation, which are deducted from his balances; Six hours are unpaid. Is this true? (2) An exempt employee with no hours of vacation time left works three hours and takes off the remaining five hours for personal leave. This employee must be paid for eight hours of work. Is this true? Why does Employee 1 receive only two hours of pay, while Employee 2 receives a full-day's pay? Is it simply because Employee 2 showed up at all that day? -- Steve, California