[competentone]

Another thought: What if the situation was that you had made some error with a survey, and using your incorrect survey, someone build a house that encroached on the neighboring lot.

If you were now dealing with the house owner and his attorney, do you think they would be concerned with being "nice"?

I wonder who did the survey when the current encroaching house was built? Or did someone just pace it out and "guess" where the corners of the lot were? If the current house owner doesn't like what she has to pay to correct the situation she's in, she can try to seek redress from the parties responsible for her predicament. You're not responsible for the errors (or "sloppiness") of others.