What are the Arguments for the Rancors, and the Verbals?

John and Susan Verbal through their real estate agents Slipup Associates sold a lakeshore lot in Anystate to Shane and Deborah Rancor for $115,000. The Rancors intended to build a house on the property, but after preparing the land for construction, they learned that a wetland protection law mandated by the Clean Water Act and administered by the (US) EPA prevented building near the lake. They sued, seeking rescission of the contract. The trial court con­cluded that the parties had reached their agreement under a “mutual, but innocent, misunderstand­ing.” The trial judge gave the Verbals a choice: they could rescind the contract and refund the purchase price, or they could give the Rancors $55,000, the difference between the sales price and the actual market value of the land. The Rancors appealed. Were the Rancors entitled to rescission of the contract? What are the Arguments for the Rancors, and the Verbals? Can anyone sue Slipup Associates and under what theory?
Instructions please submit a two to three page explanation of the issues in the case. There are multiple issues here so please be specific.