The shop I work at is ac delco certed etc , our warr covers delco parts and labor if there delco parts at any delco shop . All delco approved shops are on a same setup computer system also so if we have a situation as yours we can see what shops are in your area and recommend one and let them know we’re certed ! Delco shops also have a " honest tech " slogan of sorts saying we don’t rape etc lol . So delco feels that if your a delco shop your trustworthy . So as to say if u went to a napa repair center d.c would feel more comfy on there diag and so on and be more inclined to write a check ! Now your at a non approved facility and no one but techs no if its honestly what happened !
So in your case, if there’s a warranty claim from your shop but now in another shop’s hands that’s handled per policy, does YOUR shop pay for the repair or does AC Delco as a warranty/insurance company?