Fun:Argument from oh bloody hell that was years ago
Argument from "Oh, bloody hell, that was years ago," is a possible logical fallacy outlined by YouTube user Coughlan666. It means assuming that because someone (particularly a public figure, trying to gather support of his cause) hasn't expressed an insane or offensive opinion for a long time, quotes can no longer be used against him. This can, however, devolve into assuming that people never change their minds.
Whether the idea is a true fallacy or not, formal or informal, is debatable, but its use in defending the BNP or other miscreants is known. As coughlan666 points out "so fucking what if they said it last Tuesday?".