I also think its important to identify what the new PM considers the error in the Scope to be. I agree with the above posts, but I think if the key Stakeholders had signed off on the scope of the project-they would need to be included and determine if there indeed is an error with originally laid out scope and if they want to use the resources to address this error in scope. I think on the business side this comes down to time and money and the idea of risk vs reward. Is it worth changing the scope or will that require more resources and time that were not originally contemplated. I think if key Stakeholders are ok with changing this error in the scope, they would most likely choose to the cheapest option which would be to not hire more staff or contract out, because that would be costly.