Property encroachment occurs when a structure or physical object crosses onto your land without permission... any physical feature that crosses the legal boundary line is an encroachment if it's on your property without your permission.
You cannot reasonably be expected to receive uninvited guests particularly after a recent move so there is nothing wrong with accepting the oranges and saying, 'We look forward to being able to have you over when we are unpacked and ready for guests.' Miss Manners is only relieved that your neighbor also had the good manners and situational awareness to leave after 10 minutes.
