You are on a naive quest. It is truly a waste of time and effort to try to have a civil, fact-based discussion with any LIB/leftist/DIM. They are true-believers and their usually convoluted arguments are based on emotion, extreme TDS and underlying mental illness. It is best to not have a relationship with these people. Any relationship is dishonest. They despise you and your conservative perspective. Eventually, they would enjoy helping push you into a boxcar. Move on from them.
I found it myself. The answer is, Trump DID mock the reporter who authored the article that he was denying. That author though was Glenn Kessler. NOW Serge did co author, but the paper Trump was holding with the article in it has Glenn Kessler in the by line, and NOT Serge.