Two cases come to mind. There is the consulting software developer who does just enough to get by while carefully eliding any discussion of alternatives, consequences, or expectations of future outlays. The programmer exercises creative license when he chooses to build out crude approximations rather than represent the most likely costs and risks of minimally viable features; he walks the line when he continues to avoid generalizing solutions no matter what life cycle stage the system is at; but he crosses over when the customer asks for and expects a certain level of architectural repeatability and well-factored, reusable patterns, but gets point-to-point wired-up, one-off code instead.
There is also the all-knowing expert doctor. Recently, an eye doctor gave a prescription for glasses. I explained to him my difficulties in dealing with a previous doctor -- of being given false diagnoses, and the doctor's refusal to discuss options. Naturally, as an expert, the doctor nodded his head and did an exam, explaining to me the condition of my eyes and recommending progressive lenses. Well, the progressives were weird and unfortunately the optical shop could not get the prescription right. Everything looked trapezoidal with them, and half my peripheral world was always fuzzy. I never purchased the glasses. "That's stupid," I thought, "why would anyone want to live life with such an irritating gimmick making their eyes go buggy?" Explaining this to the doctor, I asked for contact lenses. By now he has put me in a pigeon hole, and instead of giving me a prescription that works, he gives me one fuzzy left contact and one overcorrected right contact. And I can't see anything as clearly as with my old glasses. "Give it two weeks," he says, "I've been doing this for 25 years". Well, I've had my eyes for over 47 years, and I know what I wanted, and it wasn't monocular vision with my eyes going all googley and being out of focus for two weeks. The contacts lasted for two hours before they got shelved.
In general, consultants are trained to think assertively, and the more successful consultants learn to steer clients in directions favorable to their pocketbook. Yet it is easy for that assertiveness and persuasiveness to push one down a slope of ethical blindness. The practice speaks to a lack of trust in the client's ability to look after their own interest, a parasitic paternalism emerging spontaneously from the professional relationship. At best, it leads to willful ignorance of the client's intentions. At worst, the process can bilk the client out of countless hours and lead down a path too costly to maintain.