Cannes film festival: Barnaby Thompson’s documentary on the great British director is an exhilarating delve into the ebb and flow of Lean’s peerless career and sometimes complex personal life – with a grand cast of talking heads Barnaby Thompson’s thoroughly exhilarating and enjoyable documentary about movie director David Lean is proof of the old maxim – fortune favours the bold. Lean’s career feels like more than ever like a dashing military adventure; like Napoleon or the young Winston Church