Are you under the impression that different parts of the US government typically "speak" with difference voices? This was an official government publication, that means "Who" is "The US Government", period.
He really didn't say that at all, do you not believe in transparency of the government?
Yes, I am under that distinct impression. Most noteworthy political and legal matters amount to precisely that.
I examined the documents with a leaked 0-day steganographic analysis flux capacitor, and it discovered the words "JOINT ANALYSIS REPORT" underneath the DHS and FBI logos. That might be a clue.