Not sure they were checking - That is why one importer was prosecuted I think. The way it was supposed to work was all shipments were supposed to be submitted for testing. Old mate was apparently sending good shipments for testing and sending dodgy ones for "human consumption".
http://www.couriermail.com.au/news/b...82aa3c00f9d9f6
Regardless, I find it hard to believe that a government employee in this day and age would go "off checklist". I suspect any quarantine type employees would be adhering to the regs put in place by government - not letting product through off their own back.
It was in the papers when this first came to light about it in the prawn farms, bio security qld have known about this since 2009 when it was first detected in a shipment of peeled prawns.