They most likely used a process that was successfully used for other projects; what has worked before is less likely to fail.

They most likely discussed the best approach for this project with the team and will adapt and tailor the approach periodically by reviewing and verifying the scope with the customer.

They most likely requested an increase in the management reserve; this will help the project manager to be more flexible during change requests and risk response activities.

They most likely implemented a predictive approach; this approach might limit the freedom of making changes but secures the project from unknown risks.