1) By definition, the Israelis would consider ANY shooting at an El Al counter as terrorism, regardless of the motive, or who was responsible, or what their ethnicity was. I don't think they have any magic inside instant info. And you start getting into the philosophical debate of what "terrorism" is.
2) We're once again going to see official statements unfortunately twisted around by 1) the media and 2) people that like to bash officials.
There's been a consistent problem with officials saying "no indications this was ______" morphing into "_____ has been ruled out" when quoted by the media. And then if it DOES turn out to be _____, then people frantically whine that "the gubbmint said that ____ was ruled out!"
Good example is flight 587. Right after it happened (and to this day) there hasn't been the slightest indication or evidence it was terrorism. Immediately after the attack, various official sources said there were "no indications of terrorism being involved." They were speaking the absolute truth. At no point did ANYONE official in the first days or weeks after 587 say "terrorism has been ruled out" though you'll see all kinds of people here claiming that.