Fact-based dramas are presumed or expected to be mostly real. Liberties are always taken, of course, and now and then a scene or two will be invented out of whole cloth. What matters, of course, is whether or not the inventions are emotionally satisfying. If a scene works, all is forgiven.
Off the top I can think of two such scenes that hit it out of the park. One, the “Carl Bernstein fakes out Martin Dardis‘s icy-mannered secretary” scene in All The President’s Men, which was completely invented and co-written by Nora Ephron and Bernstein himself. And two, the pens scene in Ron Howard‘s A Beautiful Mind. Even the allegedly venerated ritual of Princeton mathematics professors presenting pens to a respected colleague was completely fabricated.
Can anyone think of others? I’m not talking about lying docudramas. That’s standard Hollywood procedure. I’m talking about made-up scenes that really deliver the goods, and are even regarded in some quarters as the high point of a film in question.