Welcome to the Australian work force! It is, and always has been, 30 years behind the UK in terms of the way management treat injured employees.
I've seen and heard horror stories about people who are on Workcover for the entire 18 years I've lived here. A very good friend of mine was treated like a pariah for a work sustained injury - it almost drove her to suicide. Eventually she took a lump sum payout, (basically offered to get her 'off the books' so to speak, so she is no longer under Workcover), but also not able to claim any further ongoing medical treamtent relating to that injury. The company she works for has, and still does, make her working life diificult because they would just love it if she left their employ now as she is regarded as a liability. (Sad to say I now do the job she injured herself doing).
And yes ........ some doctors are really funny about Workcover patients. It seems to be the norm here to force people back to work as quickly as possible, even before any decent recovery is made from injury or illness. And most workplaces do now require a docs cert from day one of sickness. (You can also get a cert from a pharmacist). Check your industry award or your contract of employment for your employers certificate requirements.
The best advice is try not to get injured in the first place, although unfortunately as with Libby it was something that was unavoidable and not her fault.