I am sorry the area around your town was griefed, it definetly does suck to have the area around you destroyed. Spruceberry recently had a similar issue where we had to replant most of our new forest. However, it pains me to see our town slandered like this. As Puppy said above, he is the only one who claims our outposts, and we do not have one in that area.
It probably would've been better for your argument if you would have clicked the outpost to show off who it belongs to.
I wish HarborCity luck in repairing that area, but if you really don't want to see it destroyed your best option is to just claim it.