This home sold in September of this year for $5,300,000. There are other beautiful homes in Belevedere and Tiburon, that a good qualfied agent could help your boss with. When working with homes in this price range it is best to work with an agent in the area. A good local agent will have knowledge of properties that are for sale but may not be on the mls especially at this price range.
If your boss is interested, please have him give me a call, I specialize in properties in Southern Marin