I wonder how the hell they found that out and,more importantly,why only now
with the sudden revelations about Tether and the prices plummet across the board
They can't find anything out. They just assume that it did happen or that it is likely to have happened.
In the end we are coming down to the point where this may very well be the next attempt to defame Bitcoin's growth. Bitcoin according to most of the general opinions is nothing, creates nothing, is backed by nothing. For that reason, why should it have value?
I won't deny that I think something shady is happening with Bitfinex and Tether, but as long as there is no actual evidence backing it up, there simply isn't anything that proves it is indeed the scam or empty put people think it is. Tether is as "trustworthy" as it was a year ago. Nothing has changed in that regard, especially not because of 'research' done by whatever parties.
If the proof of fraudulent activities was present, Tether wouldn't exist anymore. Don't people here think authorities would love to see what's happening behind the scenes? If they wanted, Tether was raided a year ago already. The incentive isn't there.