Joey,
You better bend over (wrong picture, straighten up you guys) take some deep breaths, then try that pass again!!
If someone is paying you, you always have a customer/client. If you truly have no customer/client...Run, don't walk, Run Away Just as FAST as you can!!
Since when does the contractor produce their own project specifications? That is not even in the ballpark of reasonable, professional, responsible, ethical, or any other appropriate descriptive word.
I think you are confusing the roles of Consultants, Third Party Inspectors (QA) and Patsy (that's not as in Patsy Cline, that's as in a Fall Guy).
Now, an Owner should not even ask you to consider being put in such a position. The conflict of interest issues could be extensive, even though all parties are aware of the situation. That is, if you are going to end up being the TPI on this particular project. If not, then we may be looking at a possibility.
What is your business relationship with the Owner? The Contractor? The Engineer? The QC team? These are questions you need to ask yourself to see if it will jeopardize your position, your reputation, your pay, or your career.
Even reading your next post in this thread, I'm not sure we have really been given a complete enough picture to give you much advice, YET. Other than, Watch Your Back. I smell fish.
He Is In Control, Have a Great Day, Brent