That's 'cos it's a Boeing!
It happened to a Boeing first, and they had a Honeywell ADIRU. It was a very similar incident where the computers were malfunctioning and the only warning to the crew was the autopilot reacting to bad data. The crew of that aircraft also lost confidence in their machine. It gave them a false windshear warning on final approach for good measure. That was a 777.
The QF Captain's nickname according to the article is "Sully"!