Is disagreeing flaming?
Cos I'm gonna disagree, but I'll do it with a big hug if you like
If I'm thinking of the same test, the main one Samuels gave, then there is a focus on the patient describing the incident. There is a numerical score, but the test seems best as almost a guide for an interview in my opinion. Surely the professional is supposed to consider the 'essay' portions of the test and take what the patient says as important to the Dx.
It makes no sense to try to decide whether trauma happened sufficient to cause PTSD if a patient lies about the incident
causing PTSD. Folks have different stress/fear thresholds, so the diagnosis is based on the actual incidents and the patients' actual reactions to those incidents. Fictional incidents have no relevance to the Dx at all, imho. Except that they strongly indicate malingering!
It's hard to explain if you think about it like a math equation or similar. Because it deals with the human mind, what happened and what the patient thinks about that (and how their body reacts, etc) is crucial. PTSD is not a consistent entity otherwise. The same event will not cause PTSD in all people.