As I understand it, to be either flat or round is defined if the character changes/personally grows in the context of the story, not just the reader's perspective. If in scene 1 your character nearly hit something but continued to drive while listening to the game, no development. I don't know how to change it such that you have character development for scene 2.
Characters Defined by their Development:
"characters as described by the course of their development in a work of literature. Flat characters are two-dimensional in that they are relatively uncomplicated and do not change throughout the course of a work. By contrast, round characters are complex and undergo development, sometimes sufficiently to surprise the reader." - Britannica
Round Character:
"A round character is a major character in a work of fiction who encounters conflict and is changed by it. Round characters tend to be more fully developed and described than flat, or minor characters." [source]
Flat Character:
"Flat characters are minor characters in a work of fiction who do not tend to undergo substantial emotional change or growth. Flat characters are also referred to as "two-dimensional characters," and are the opposite of round characters." [source]