In 25 years of bunny hunting in WI, I have found that rabbits shot later in the season, when the temps are colder, do taste better. Not really sure if it's a subjective thing.
I would assume that rabbits down under would have a better chance of having worms and such as the temperatures remain warmer year around.
As for tularemia... I define "rabbit fever" as the uncontrollable urge to get up early on a frigid morning, leaving the warmth of a comfy bed, to tromp up and down hills through thick brush in the hopes of getting a shot at a long-eared rodent.
NRA Life Member, SAF contributor.