Although the 4th Circuit broadened the scope of Concepcion v. AT&T Mobility with its ruling in Muriithi v. Shuttle Service Express, it opted to limit the Supreme Court's decision in an earlier case. In Noohi v. Toll Bros. Inc., the arbitration clause in question was contained in the purchase agreement between a developer and home buyer.

Maryland state law requires arbitration agreements to be supported by mutual consideration independent from the rest of the contract. In other words, each party has to give some value to the other. Because the home buyer in Noohi was obligated to arbitrate, while the developer was not, the 4th Circuit ruled the arbitration clause unenforceable, in spite of the developer's argument that Concepcion's pro-arbitration stance should preempt Maryland state law on the issue.

“While the 4th Circuit was willing to read Concepcion broadly as to class action waivers, it wasn't willing to take that ruling and start invalidating other state law provisions that it typically has been found to control in arbitration agreements,” Littler Mendelson Shareholder Bill Allen says.