What is the right thing to do?

Why not move it back to his own property that he is renting out. Let his tenants keep under a tarp. Once it's in his own yard, you're done.
Kinda what I was thinking. A buddy left his boat in the back yard of his rental in Manhattan KS when he left Ft. Riley. He would write (before cell phones) a couple of us and ask us to make sure the boat was still there. It was when I left for South Korea.