My two cents-
If a person truly didn't know they were trespassing they would politely apologize, explain there route of access and immediately turn and leave.
I have personally been tracking a poor bow shot on a deer and found myself on private land without any idea I even left the state forest.
Stumbled on the owner and I did as described above. He followed me out and I showed him were my stand was on state land and the blood trail. Once he believed the story he helped me track and retrieve the animal on his property.
Uncomfortable yes, professional and manageable, yes.
I am only telling you this as one can get angrier and angrier and every case may be a little different.
Good luck.