It depends on the manager's motivation and knowledge. The law protects town or government officials from liability (from being sued for) mistakes made in good faith. So if the manager, even incorrectly, believed this and thought he was doing his job by advising people of the local ordinances, etc., he is not liable. There is no legal obligation to provide notice to you, and they can just answer potential buyer questions without making you aware of the issue, though a lack of notice to you about some alleged problem the town claims to be aware of may be evidence of a bad motive (see below), since if there is anything that you should be doing vis-a-vis the trailer, the town should logically be making you aware of that.But if the manager knew this was not the case and is giving misinformation to buyers for some improper reason (e.g. he has some grudge against you or your family; or he hopes to scare off buyers, then have some friend or family member or associate of his make a low-ball offer to you), that would be illegal and you could sue.