I think the big issue here that nobody has mentioned is that the SELLER is an agent, or even, possibly, the LISTING agent of the house. Is that right, Jc?
If that's the case, the State of MN mandates that the owner/seller disclose anything they know to be true with regard to defects of the property. And, an additional layer of protection is that agents are bound by their licensure to do the same, only with even more diligence!
HOWEVER, if there is a defect that the seller/agent did NOT know about but was discovered later, there is no way they can be held accountable for same. And, unfortunately, the burden of proof is on you as the buyer to prove they had prior knowledge and did not disclose. Sorry. :(
Consult an attorney about your options if you decide to pursue litigation.