Speaking to some of the Jetstar cadets it appears the biggest problem is that OAA has become too big and disorganised. I also guess all of the ownership changes going from GFS to OAA to CAE in a few years wouldn't help.
Apparently the Jetstar cadets needed to be very motivated and organised to get the training resources they needed to complete the course. Some of the cadets would book half a dozen flights at a time a month in advance to ensure they could get planes and instructors.
Another problem appears to be they don't allocate set instructors to students, which makes the training a bit fragmented.