read the 58 page report from the fbi wherein they admit it happened at least once - also guccifer even tho not charged with accessing her server admits to doing so, and Clinton said she wasnt hacked by anyone including guccifer is a liar or Clinton is covering her tracks.
and to help the cover, guccifer was charged hacking bushes computer
I'm certain that if Israel had a look then they would be smart enough to cover any trace