Tiger doesn't employ anyone directly to do their maintenance. It's completely farmed out to 3rd party providers, of course at the lowest cost. They get the flexibility to tell the providers to only do what they're told to do.
Of course putting yourself in the 3rd party providers shoes, if you're getting paid bugger-all to service the contract you're only going to do what you absolutely have to do as per the terms of the contract.
If there are concerns from CASA about maintenance standards, then its either the fault of a major 3rd party provider in this country (which I'm sure if it were at fault it would be in trouble, not Tiger), or its the department which is controlling/scheduling what maintenance is to be done within.