Evidence.

The CO of the Squadron was waiting for his two F111s when they taxied in to their hangar bays. Two days later he was waiting for me.

'The future of military aviation - indeed aviation in general in Australia is at a crossroads,' he began. 'The Minister wants us to deal with this incident in a way that ensures continuing confidence in our responsible use of airspace to conduct our training.'

My legal boss had put it more bluntly when he'd tasked me as the Prosecuting Officer. 'If you don't get convictions, don't bother coming back.'

The two pilots had each flown a low level 'spacer pass' by the control tower at the bombing range 30 seconds apart. Their speed was just below the sound barrier, causing a sonic 'disturbance' that blasted the tower into $100,000 worth of damage. The range controller was showered in glass but otherwise unhurt and with a great story to tell.

I arrived at the Base on the Friday. The trial was to begin on Monday. Everyone at the Squadron was as respectful as my rank required in assisting me to gather evidence. But no-one wanted to help me to convict two of their own pilots.

'There was an airman who filmed it,' the CO had told me. I found him and asked if I could have a copy of the video. 'I gave it to the Squadron Safety Officer,' he told me. The Squadron Safety Officer shrugged. 'I deleted it,' he said. It wasn't the smoking gun, but it would have helped.

Three years later and I'm visiting the Directorate of Flying Safety in Canberra to give some legal advice. I'm chatting with the two Squadron Leaders about the F111 trial and ask their opinion about some of the questionable technical evidence given by the pilots.

'Would you like to see the video?' one of them asks. My jaw falls open.

My role as Prosecuting Officer in a Defence Force Disciplinary Act trial was to use an adversarial process to present admissible evidence that proved beyond reasonable doubt that two pilots had broken the law and should be punished to deter both them and others from doing the same. In SPEAR terms I was helping to Patrol the Space.

The role of the Directorate of Flying Safety is to use an inquisitorial approach to gather information about aircraft incidents to learn from them and pass on those lessons to all pilots to keep them safe. It was helping to Create the Space.

Same information - different Widgets.