Wrong. They were fired after their audit in September 2017 which is available here:
https://tether.to/wp-content/uploads/2017/09/Final-Tether-Co...
https://tether.to/wp-content/uploads/2017/09/Final-Tether-Co...
It explicitly states on the first page that it cannot be relied upon.
When Tether posted it (https://tether.to/announcement-transparency-update/) they stated " These consulting services do not constitute an audit or attestation engagement, which would include a significantly expanded scope of procedures and take substantially more time to complete."