This is fallout from the Snowden leaks.
No, Brandis doesn't need an excuse for this behaviour, he was like this before Snowden was born. His predecessor (and mentor) from the Howard government was Ruddock, Ruddock was the guy who threw out the Magna Carta in order to make a political prisoner out of David Hicks, it was the most shameful act of any Aussie AG I have witnessed in the last 50 odd years. I will be very surprised if Brandis does not sink even lower than Ruddock (assuming that's possible).
People who thirst for the power that comes with the role of AG should somehow be banned from applying for the job.