Western Australia port worker here. I work a little further north but today at toolbox meeting I got the rundown on why this occured.

Essentially the department responsible for deciding weather or not a ship can berth with regards to covid is seperate from the fremantle port authority. They had received info that there where fevers on board but decided it was safe to let this ship dock. This, coming from the perspective of a seperate port worker in WA, is egregious negligence that was allowed to come to fruition because, again, the department that made the decision was seperate from the port. My guess is they just kinda assumed there would be no contact and have absolutely zero knowledge of port operations. This is unique to freo rest assured and the rest of us are sighing pretty hard at this bullshit. At the port I work at we have a 14 day exclusion period before health checks are made at anchor and relayed back to the port. Not hard to get this shit right but by the sounds of things the sheer size of freos operations has also played a major role in this.