Av Herald reports that the ground handling company has been suspended from operating at this airport until it is recertified as compliant with their NTSC recommendations. So it appears that it was the towed ATR that was where it was not supposed to be. The controllers involved were put on "emotional leave" due the stress/shock of the accident.
Filter that through your own opinion of Indonesian bureacracy as you will - I'm taking it at face value for the moment.