Your claim appears to be wrong according to this interview (and others I have found)
He denies the “Truther” claims but rightly condemns parts of the 911 investigation.
http://www.youtube.com/watch?v=ihCP3cfS88E
What do you think about the Israelis that were found celebrating the collapse of the WTC? Were they antisemetic as this probably set back relations with Israel more than any other single event except, perhaps, the USS Liberty
Those were Palestinians, not Israelis. Best learn what your talking about if you are going to post here.