buyers are trying to sell trailer back to sellers

[mygalsal]

My husband and I recently sold our trailer. We let the buyers know upfront that we did not own the land and we told them who did. My husband said the man was happy to hear who owned the land because he had dealt with him before. Apparently the buyers wanted the trailer to rent it out but the land owner told them he does not allow that. They either had to sign his contract or move the trailer. The buyers have contacted us and said they are building a case against us on a morale charge. They are saying we should have told them before they bought the trailer that they couldn't rent it. Our argument is that we didn't know that, our contract when selling the trailer said nothing about the land, and our only responsibility was to the trailer and the condition it was in. We also feel that it was not our job to do their homework and find out if they could do what they wanted with the trailer before they bought it. They should have contacted the owner of the land before purchasing the trailer. My question is do they have a case or are they just trying to scare us.