Towing incidents can have many factors.
Was the stationary aircraft parked in the correct spot? Was the area clearly marked with lead in lines, and wingtip clearance lines?
Was there a wing walker? Did he have proper means to communicate to the tug driver? Were the wing walkers employed by a different company, and therefore may have had different set of signals to communicate to the driver with?
Speaking of the tug driver, was he hooked up forwards or backwards? This can make a big difference for situational awareness and visibility. Some companies SOPs state that tugs are always to be hooked up facing the aircraft under tow when towing near hangars / other aircraft / tight parking spots. Does the company in question have such rules?
Was there someone riding brakes? (News report said there was nobody on board but I assume they mean passengers) Could the wingtip in question be seen from the A330 cockpit, and if so could they have prevented the incident if they were watching?