“Mr. Downing discloses that Mr. Manafort was interviewed by the Justice Department and FBI in 2014 as a “witness,” not as a suspect, in a federal investigation of a former Ukraine president.
The information was resurrected by Mr. Mueller three years later and used to get a grand jury indictment.”
I'm not a lawyer, but does this even matter? I would assume you're expected to tell the truth regardless of whether you're a witness or a suspect.
I guess the one legitimate point would be whether he was read his Miranda rights and given the option to retain legal counsel.