Firstly, Tether banks with an organization in Panama (Panama Papers anyone?) It's no surprise they aren't willing to do any kinds of auditing since banks in that area are known to house illegal activities.

Secondly, it is almost a guarantee that prices of all cryptocurrencies will fall especially since a significant portion of the pump up for bitcoin was as a result of tether. The following image details when tether was printed and how it correlates with bitcoins price increase.

Stay safe!