To answer your question: "How do you know that someone allegedly photographing 911 was an Israeli agent?" Because the FBI stated this fact on the Fox news report which was abruptly removed by evil Zionist entities shortly after the broadcast!
Do you think it was just a coincidence that Larry Silverstein (Israeli dual citizen) "had a dentist appointment" the morning of 911 so he was conveniently absent from his building that he normally ate breakfast at every morning? Do you think Larry Silverstein meant when he said "they decided to pull it" he was talking about removing the firemen from building 7? To educate you further building 7 not hit by a plane was a bottom to top controlled demolition the other 2 buildings were top to bottom controlled demolition. Any idiot with eyes can see video that the buildings were exploded in to pulverized concrete dust.