My friend and I were first introduced to Mike Leigh through the 1993 under looked film “Naked”. It is our running joke/belief that David Thewlis vagrant, philosophical rapist, was just Professor Lupin before his tenure at Hogwarts Academy of Wizardry and Witchcraft. So maybe you can make an argument for Timothy Spall reversing from mild mannered blue collar worker in "Secrets and Lies" to a conniving weak willed wizard in "Harry Potter".
