This video is extremely well edited. Howard Dead went on Olbermann's show and said that people should not call a sitting president a 'Fascist'. It does not appear that Dean knew about Olbermann's use of the word 'Fascist' against President Bush, but Olbermann clearly remembered.
Just watch the clip.
Video embedded below. (From http://www.olbermannwatch.com/archives/2009/03/john_dean_says.php)