I think you handled it well. Because 30 feet on an unmarked line is real subjective.
As stated in this thread several times already, people who work in the woods and have to know how to find and mark boundaries will testify, many landowners have no idea exactly where their boundary his. Many will say they do but the compass and hip chain often shows a completly different scenerio. Something that often goes bad, ecspecially with the landowner who actually owns less ground than they thought.
I wish all the fellas who said they would have went ballistic would stop long enough to think, unless your line is marked on good deed calls, a fence, etc..., you might be wrong about your supposed known boundry. And 30 feet is 8 steps. Just cause grandpa said the line went through here doesn't mean it did unless it has been verified. And a property line is that, not a general area, so going through here is subjective to which side of the actual line you are standing on. Just make sure you put yourself on the opposite side before you blast someone for an innocent mistake, cause I am willing to bet you if you have NOT had the line verified, you are going to be wrong 50% of the time. Just my expierence. God Bless