I wouldn't take Weirdo as his word since he has zero credibility.
In fact here is what Comey said in an interview provided by this source[time.com] April of 2018
Note this is before his book is released but about the book's content.
"JAMES COMEY: That’s right. She agreed. Loretta Lynch I had a great relationship with and still have a lot of respect for. And she said, “I agree. But call it a matter.” And I said, “Why would I do that?” And she said, “Just call it a matter.” And I didn’t know exactly why she was doing that, but I decided in that moment that the whole world would miss the distinction between investigation and matter. And so I dropped it at that point. At my press event, I said– used the term matter, and I was right, the press missed it and said we’d confirmed an investigation."
Thank you, Dane