Don't simply take the Builder's word for it. He should provide you with a written authoritative source for his opinion, just as your inspector has. I recommend this so that repairs can be made under the Builder's one year warranty. If you have an Extended Warranty it's still important to get the report to your Builder within the first year. This is when the warranty is most comprehensive.
Most warranties cover only major structural items after the first year.
The warranty company decides what is a structural defect. Usually an item has to fail before they consider it a defect. I consider all structural defects to be unacceptable. They will likely cause something to need repair sooner or later, and sooner is usually cheaper to repair than later. Lots of other Standards may applie to a given defect.