You are probably from Il, and I am not disputing what you say. But I thought the NICS check was Federal law.
States are responsible for the background check done when selling a gun. NICS is the standard resource to do that. Many states, including my own, allow an existing state firearms license or CCW permit to take the place of the NICS check.
You would be correct.
I am from Michigan, not Ill, but in several states, including Michigan, if a person possesses a concealed carry permit or state issued FOID, they are not required to go through a NICS check when purchasing. We still have to fill out a form 4473, but do not need the NICS phone call.
The past four guns I purchased I only flashed my CPL to the FFL, and he recorded that information on the 4473 in lieu of a NICS approval number. (Line 21 on form 4473)