Moses directed the tunnel be finished with a different method for finishing the tunnel walls. This resulted in leaking and, according to Moses biographer Robert Caro, the TBTA fixed the leaks by using a design almost identical to Singstad's original. Singstad later claimed that Smillie had caused "excessive" leakage by not using Singstad's experimental caulking design to prevent leaks. Smillie denied that the leakage was excessive and that Singstad's caulking method had been replaced because that method was actually the cause of the leak.