...when does a person accept that their ambition is leading them in the wrong direction?

I think there's an important difference between hardship due to you being on the wrong path, and hardship due to bad conduct by people with power you encounter along that path. I also think conflating the two smacks of victim-blaming, so getting the difference right is important.

For example, say a medical student is distressed because an attending physician frequently overreacts at small, med student-type mistakes and berates them mercilessly. I think we could all agree that the problem here lies not with the student's ambition of being a doctor, but with the attending's poor temper. If the student can't overcome their distress at seeing blood or other bodily fluids, then the problem is with their choice of direction and the fact that their capabilities don't match their ambition.

In this case, Bond's ambition to be a lawyer doesn't appear to be the problem. The problem is a judge like Kozinski who would take advantage of his power over his clerks' careers.

I think we need to be careful not to roll human misconduct (sexual and otherwise) into the list of things that we accept as obstacles to achievement. There is a point of distress and suffering where a person should stop and reevaluate if their ambitions and choices aren't right for them, but we shouldn't accept it when the malice or misconduct of a person's superior leads them to that point.