I was in the vicinity of a news story once and I interacted with the press. A reporter from a local news station. She asked me what I saw and took notes. There were two follow up questions: "did you notice anything else?", and that's it. The report didn't really include any of the extra details that I provided, just what you could see from the street. It included a clip from a different witness who was much more chatty and added their own... flair.
I say all this because in my limited experience, the embellishments come from average Joes who are eager to say such things to reporters.
I agree but I think it's both. Reporters will know if a witness/interviewee is too straightforward for their purposes and will move out until they find a juicy enough narrative. That way their ass is covered.
I say all this because in my limited experience, the embellishments come from average Joes who are eager to say such things to reporters.