This is my first comment via this method I hope I am doing it right.
I also use Josm and keep the version updated.
I don't recall altering the state forest boundary. I only realigned the ANP. Sections of the ANP were replaced by merging from boundary data imported from shape files but I checked the sections I was changing for other relationships before doing so. I vaguely remember that little bit of state forest being there at the time and I deliberately didn't remove it even though it overlaps the ANP boundary which also makes no sense. If you look at a very large "woods" area that has a southerly running boundary near by it doesn't make any sense either. I do my best to make worthwhile edits check the consequences very carefully. The ANP boundary was a massive job that took me several days and many hours.