A new biography, The Double Life of Paul de Man by Evelyn Barish, has documented that he not only was a hypocrite, but also a convicted criminal (some sort of financial cheat), a bigamist, and a liar about his academic credentials. Who knows if this discredits his notorious philosophy -- as far as I know the initial revelation of his early propaganda articles had no particular effect on those who still adhere to his "principles."
To quote a review of this book in the Chronicle of Higher Education (with my red emphasis):
"'I would suggest that de Man was the antihero for our times,' Barish writes in the epilogue, 'and his pattern of secrets, crimes, flights, and self-reinventions is the stuff not just of drama, but of the madness that convulsed his own life and that of Europe in the era of Nazism.'
De Man's stance, the stance that made him famous, was that facts were unreliable, language was slippery. For a fugitive running from unpleasant facts, and one for whom lying was second nature, such a worldview was both natural and useful. 'The people that love de Man and continue to support him fundamentally say that there is no necessary connection between what a person does or says in his or her private life and what his or her ideas are,' said Barish. 'I'm not of that position.'"