According to the French forum, the tug disconnected and the marshaller connected with the headset told the crew so. At that moment, the crew spooled up the engines quite severely and started rolling, sending all personel on the ground scrambling away to save themselves. The guy at the headset was still connected, so the all clear had definitly not been given.
Same thing did happen to me many moons ago as a load controller at ZRH with a DC8. Thankfully the tug was already out of the trajectory and all I had to do once ATC told the guy to stop is to go retrieve my headset which had been ripped of my head. They later told me they had not heard me shouting at them to stop....
The same message also sais that it was to be the last flight of the commander before retirement and they had a huge party of honor waiting at TLV to meet the plane. What a pity to end a career like this!