Duh
"The results prove that automatically identifying changes to certain types of Land Parcel Boundaries – especially, drains/ditches/dykes, walls, or fences (which are smaller than the spatial resolution of the input imagery data) – is very difficult"
And in those scenarios a PITA for people too, refining algorithms in those cases is still not going to get "decent" results (as in better than human and in high 90s accuracy level), only option is higher resolution imagery.