The British government is defending its handling of the withdrawal from Afghanistan. That's after a whistle-blower labelled it chaotic and dysfunctional. Raphael Marshall, a former junior official with the British Foreign Office said the process of choosing who would be evacuated was arbitrary. He said thousands of emails pleading for help went unanswered, and that some of the Afghans left behind have since been killed by the Taliban. Sarah Morice reports.