Doesn't John McCain wish Craig Murray was a US Citizen so he could subpoena him to appear before the Senate and name the leaker.
You can bet the farm that the political establishment is desperate to know who the "leaker" is so they can shut him/her up. You can also bet the farm that the CIA would be more than happy to do the job.
It doesn't play into their "the Russians did it!" propaganda and the blatant ramp-up to war some in Congress want us to be in.
The CIA is making stuff up to create conflict with Russia.