This is a boat entirely of the NSA's making.
They compromised RSA, remember that?
They wiretapped everybody, remember that?
They stole internal corporate communications, remember that?
And, in all cases, the NSA was doing things far worse than the tech folks even imagined. And, in all cases, there were denials all around. Until there weren't.
So, one one side we have Bloomberg: a company who makes a living digging up market moving information. A company whose bottom line is going to be affected by this. A company who will be on the receiving end of no end of lawsuits if they are wrong.
On another side, we have the NSA, the PLA, the KGB, etc., all of whom are known to be malicious actors who would all do exactly what was described.
And, on another side, we have a whole bunch of rich companies that stand to lose quite a lot if it comes out that they were significantly compromised, or, worse, actually cooperated with any of the above entities.
I think my Bayesian priors are quite well calibrated, thanks.
After a few weeks, if we still don't have physical evidence in hand, I'll update my priors.