Yes. I have been one of those. Where do you think the externals get the expertise needed that is particular to the business? We can be professional about it and try to point out the real exceses or answer generic questions, redress and inform on specific knowledge traps or consequences of answering choices placed in front of the customer, but in the end it is still a business that is running 'right-sized' being required to drop everything for a few years to assist an IT transitioning project?

Overloading the customer is one of the simplest ways to make sure ít is not your fault when things most often go south.