With the game goalless, Hangeland was shown a straight red card by referee Lee Probert for a two-footed challenge on Lee Cattermole.
"By the letter of the law it was two feet off ground," said Jol. "I still thought it was harsh because there were other incidents where if they judged them by the letter of the law then there would have been fewer players left on the pitch.
"Everything was against us - everything."
Sunday's loss at Craven Cottage was Fulham's fourth of the Premier League campaign.