CNET News.com has confirmed that two Apple executives–including the Macintosh unit’s head of engineering–have quietly left the company in recent weeks. “Tim Bucher, who became head of Mac product engineering earlier this year, left the company on Nov. 15. An Apple representative confirmed the departure Monday but did not give a reason. Also departing in recent weeks was Mark Wilhelm, the vice president in charge of the company’s AppleCare support unit. Apple has not named a successor for Bucher but said a team of workers is overseeing engineering efforts and reporting to executive vice president Tim Cook, the leader of Apple’s Mac unit and also the head of the company’s overall sales and operations. Apple declined to offer further details on Wilhelm’s departure or on who is running the support operations in his absence.”