You have to remember, that by them endorsing you to test your rifle, they are opening themselves up for liability. It doesn't surprise me in the least that they just want you to send it in. Think about all the guys that have guns, that probably shouldn't... I know I have to supervise my wife very closely when she holds a gun :0). If my wife has a FTF or something, I am taking the gun away from her, and clearing it for her. DPMS cant know who to trust.
Let us know if you have to send it in, or if the shop helps, anxious to hear what it is.