$9 flights to anywhere sold out in a flash, for those that could somehow log on to AIR's system. You're right on your second point. Getting giardia which is widespread in many of our rivers and streams is no laughing matter and from first hand experience I can tell you its extremely debilitating and you can end up very sick for a few days.
$9 to Invercargill would have been pretty cool if I could have got into their system. I did check for later this month at a time when I could possibly go down and it was ~ $400 each way.
Its actually not panic, its a rational psychological human response according to a psychologist on breakfast T.V. this morning. People are concerned for their future so want to do something to proactively mitigate the risk.