I caught it before the rest of the fence went up and they moved it but only after making comments.
That was a badly worded sentence. I talked to the neighbor and kept it polite. Which was hard since I had the flu and he is not a very friendly guy.
He raises dogs. A couple of times the dogs have been loose and have run over to me to say hello when I was at my gate which as fine. Just dogs being dogs. He walked up to me both times, within arm reach since his dog was at my feet jumping on my leg, picked up the dog and walked away. Not a word of hello, sorry, good day. Nothing. He does this sort of stuff all of the time.
Anyway, the day I talked to him, I kept it friendly. He made some comments I ignored with great difficulty. I showed him the corner pipe, a compass to show roughly the line, and thankfully we found a survey pipe that I had put in along the line. Not much he could say at that point about his fence line. But of course he did. I just walked off and let him figure out what he needed to do. The contractor was mouthing off that someone was going to pay for the change... I checked later and the fence looked like it was on his land.
Course most people would have known where the line was in the first place. And then be thankful I told him before he really spent some money. As it was they only had to move a 6 or so posts.
Happy,
I would think you could find the county/state rules online to check the setbacks. Course you could just call and ask. Most likely faster.

And if you think he crossed your line now or the mound will slide over your line or he is over the setback I think you have to do something. If you have to do something its then a question of do you pay for the survey or should he? In my case I just paid for it myself. I had other work for the surveyors to do anyway but that line cost about $400. And since I did not have time to keep it cleared and marked like I knew I should I'll pay for it again. But not a third time.

My neighbor should share the cost but given his personality its just easier to save up the money than dealing with him...
Later,
Dan