Looking at the raw transcript from the deposition can be horribly misleading at best. The transcript doesn't capture tone, accents, stress level, pacing, volume, and a variety of other things. A dramatization allows you to color the scene in a variety of ways that tell the story in radically different ways.
Think of saying "wow, that's a great idea!" to your best friend that has a great idea. Then think of saying that to the office idiot who just suggested they can rebuild your entire system in a weekend.
"Interpreting tone, accents, stress level, pacing, volume, and a variety of other things from a transcript" is a pretty good description of a director's job.
This project just uses the verbatim transcript as a screenplay, and runs with it. They are very honest about the fact that they are aiming for something between faithful re-creation and entertainment.
Think of saying "wow, that's a great idea!" to your best friend that has a great idea. Then think of saying that to the office idiot who just suggested they can rebuild your entire system in a weekend.
Disclosure: I work in speech recognition systems.