No rating, no bond. It's not aimed at cost recovery but as a disincentive to leaving for greener pastures overseas before your five years are up. If you are terminated (or leave of your own volition) during the training there is no financial penalty.
There is also a probation period after gaining the initial rating.
If you fail to meet the standards you could be terminated or you could be re-coursed (starting again on a subsequent course).
Basically you need to pass each phase of training to proceed - you have an exam, a supplementary if required and failing that means you're shown the door. Resources and time are limited so there is scope for some additional assistance but not a huge amount.
Sorry, don't know about coming back for a second bite.