"It was a kind of criminal negligence to deal with some of the problems that were staring us in the face," he told the public hearing.
"In other cases, I think there were people that were just like rabbits in the headlights, they just had no idea what to do, and their performance was appalling."
Perth Archbishop Timothy Costelloe also gave a damning assessment of the way allegations of sexual abuse had been handled.
He said there had been a "catastrophic failure" in Church leadership and that the abuse of children was at odds with what the Church purported to be.
The archbishops said they were taking a more collaborative approach to decision-making in their dioceses.
"The problem will always be there to potentially rise again unless that issue is dealt with," Archbishop Costelloe said.
He said in the past, the Holy See believed itself to be "so special, so unique and so important" that it was untouchable.
"That's probably the way many bishops in their own dioceses might also think of themselves – as a law unto themselves, as not having to be answerable to anybody, as not having to consult with anybody as to being able to make decisions just out of their own wisdom," Archbishop Costelloe said.