Was that the point of the stop and warning? The stop sign? I’m not up and up on all the details.
Failure to signal lane change...and possible rolling stop.
She ran a stop sign right in front of him, he made a u-turn and got behind her, then she changed lanes in front of him without signaling.
I suppose he decided to investigate at that point. He never mentioned the stop sign running to her, but did cite the failure to signal lane changes.