The tragedy forced the previous boss Tony Hayward to resign and BP to opt for a US citizen to fix the huge problem. Hayward's predecessor, John Browne, who oversaw BP's momentous take-over in 1998 of Amoco, Dudley's previous employer, and helped turn BP into a true major, had also stepped down early, after losing a court battle in 2007 to keep secret details of his personal life. At Shell Chairman Philip Watts's time in office was cut short in 2004 after the company overstated oil reserves. The same year, the chairman and CEO of Statoil quit following a bribery scandal over Iranian contracts. To complete the picture of a decade of abrupt changes, ENI had to bring forward its succession plan this year and replace its long-serving chief Paolo Scaroni, partially because it learnt that his successor in waiting, Claudio Descalzi, was approached by Shell to become head of exploration, according to industry sources.