Thinking about this, the magic words might be 'track direct to' as opposed to 'route direct to'. ANSA the AIP in oz requires the pilot to 'immediately position on track' once within range of an aid. So if you fly into range of a VOR, and are not on the correct radial, you are supposed to get on it immediately (in practice, an intercept is flown). Therefor if the instruction is to 'track direct to' and the pilot is navigating the old fashioned way (with reference to ground aids), he may be perfectly entitled to perform some unexpected manouvre. He's probably not in RNP5 airspace though!
We all get a bit used to the modern RNAV equipment I think, allowing the pilot to indeed 'track direct to...'