It did not sound to me like the worker owned the RV in this case. It sounded to me like the farm owner had the RV there, probably as a place for the employees to live.
Which is often the case, especially around Wellington. It could be much cheaper to provide modest housing for your staff (RV, barn apartment) than to pay them enough of a salary so that they could afford to pay rent somewhere off the property.
Plus that way you have them somewhat available 24 hours a day if there is an emergency. Sick horse, late return from a show, etc., etc.
In theory, anyway. In this case, unfortunately, it turned out that the worker was the emergency.