Not good airmanship by the other pilots (if pilots moved the aircraft), however airmanship these days is somewhat non existent by some of the newly trained pilots theses days due to dismissal training and checking standards within some areas of the industry.
If the pilot of the aircraft that was moved subsequently flew it out without any action, apart from being disappointed because someone moved his/her aeroplane without their consent, all bets are off - case closed and get on with life. However, if the pilot refused to fly the aeroplane out without an engineering inspection due to potential damage, report it to the police and CASA before the next flight to enable them to investigate.
I doubt that the police or CASA will do anything if the pilot flew the aircraft out and elected to report the event after the aircraft left Roto.