The point is it begins as their idea(s) but since I am writing it, I am in a way, editing their thoughts and influencing the final product with my own thinking. Thus it can transform into what I think is the better or funnier or most acceptable way to express their thoughts, and alter the main idea.
As an example, if Aubrey had been writing/editing the script for Unanimous. she would have automatically used the term "old school" instead of old fashioned. I actually think she was correct because old school has some positive or neutral vibes, while old-fashioned sounds a tad negative.
I don't know if I am being clear here,(so much for any writing talent ) but my opinion is that when Lisa or Aubrey take over the writing, the final product is a collaboration, but the writer absolutely is accountable.