Earlier quoted context omitted.
I'd argue it's still unethical to put others at risk due to your own incompetence. I wouldn't offer to rewire someone's home because I'm not an electrician, and their house could burn down if I do it incorrectly.
> due to your own incompetence. Are you still unethical when you don't know about your incompetence? Can you be unethical if you had no ability to know that what you do is unethical?
You're correct that reality can be more complicated, and it depends. I can imagine a scenario, e.g. the plot of "Manchester by the Sea" which doesn't seem completely unethical. I find it hard to believe in this case that he was that incompetent. I think he took what he believed to be a calculated risk, and I'm guessing he didn't go around broadcasting that information to the other people on the tour.