Options: 1) Medical condition 2) Looking at phone 3) Bee or snake in car
Might have been passing. Pics of the scene show that passing was permitted in one directio.
That actually happened to me. Years ago I was stopped at an intersection with the windows rolled down on a warm day and a bee flew in. As the light turned green and I started moving, the bee decided to land on my hand while it was on the steering wheel. I'm swatting at it like a maniac, car is swerving all over the place. I just lost all control for a few seconds. I'm darn lucky I didn't hit anybody.
Could also include dodging a coyote or deer...