Might filing a lawsuit be an attempt to gain control over the situation?

I never saw any evidence of a boundary violation, only driving on a public street.

Her actions didn't seem unethical to me, but the way the ethics are set up exonerates therapists from taking responsibility for anything that goes wrong including harm to the client, shield them from discomforts, and provide an excuse for taking the easy path rather than doing the more difficult work that the most competent Ts do.