1. A client didn't know what they wanted, had 60 million to spend on figuring it out, and hired a firm that would let them spend 60 million.
2. The firm was incentivized to provide a nice looking underestimate and then adapt as new work was discovered.
3. The firm continued getting paid as long as the client was happy.
4. The client did not want to be told that the project was a year late in advance.
One unfortunate aspect of the customer is always right is that the customer may often be very wrong.