Iain Conn, who will succeed Sam Laidlaw as chief executive of Centrica, would have been a dead cert for the top job at his current employer, BP, were it not for the Deepwater Horizon oil rig disaster in the Gulf of Mexico in April 2010. The subsequent PR fiasco terminated the BP career of the then chief executive Tony Hayward — who seemed crushed by the episode, but recovered to make a double fortune at Genel Energy and Glencore.