director ownership, page-69

BHP Billiton Ltd non-executive director Alan Boeckmann bought 375 American depositary shares (ADS) representing 750 BHP Billiton shares for $US27,251 ($A29,437) on the New York stock exchange on November 11, 2009.

American depositary shares a vehicle for foreign corporations to list their ordinary equity on the American stock exchange.

OK
Now lets put that in perspective

BHP
MC=$126.17Billlion
Number of Directors=12

And as you stated ,ONE director bought 750 shares in 2009!!!!

Sorry ,but if this was on Mythbusters the theory is BUSTED