Possibly, what they said was..."it's the radiator SUPPORT bushing." You might call that a body/frame bushing, because it looks like one, but it's located under the radiator support. It is commonly refered to as the core support or radiator support bushing or even donut.
There are other things that can cause such a fender misalignment, but the core support bushing is certainly a possibility.
If I may offer this...if you are already this uptight about trusting the word of this shop, you might want to select another shop. On the other hand you might want to make sure you aren't being a touch paranoid as well as not knowing enough of the technical "lingo" to determine if you are being BS'd or not. JMHO