Huddersfield ended the game with nine players but still managed to take a precious point in their Division Three promotion push.
It was Orient who grabbed a sixth minute lead through top-scorer Gary Alexander - but Town were back on terms three minutes later when Andy Booth slotted home.
But Pawel Abbott saw red on 26 minutes when he felled Orient defender John Mackie in an off-the-ball incident.
Referee Trevor Parkes consulted with his assistant before sending the Huddersfield Town striker off.
Then Booth went seven minutes from time when he picked up a second yellow card for dissent.
Huddersfield Town manager Peter Jackson fumed afterwards: "I suppose the fact that we ended with nine players means that I've got to be delighted with a point. It was a good game but the referee spoilt it totally." However, the Town boss felt the dismissals could jeopardise his side's promotion push and added: "With two keys players missing during the run-in, his decisions could cost us promotion." Orient manager Martin Ling admitted: "Before the game I would have been happy with a point but I'm only half satisfied because we played for so long against ten players. We created some chances but not really enough." In a dramatic start it was Orient, looking for their first League win in nine games, that were given a dream start when Chris Tate's quickly taken free kick caught the visiting defence napping and Orient skipper Alexander fired the ball home from a tight angle.
But Town's response was immediate and Abbott's run took him clear of the home defence and in a scramble that followed Booth fired home from close range - only to pick up his first yellow card for prolonged celebrations.
Orient had a penalty appeal turned down shortly after when Warren Hunt was sent tumbling in the area and Huddersfield keeper Paul Rachubka pulled off a super save when Andy Scott burst clear.
After the break, Booth rattled the Orient post but the final 40 minutes were played almost exclusively in the visitors half as Justin Miller, Mark Peters, Donny Barnard, Ciaran Toner, Alexander and Jabo Ibehre all had chances to win the game.