Contractor failed inspection wants to charge more

[Christian Allen]

I hired an electrician to install a complete hardwired and interconnected smoke detector system in my multifamily property.  The fire inspector came out today and did not give a sign off because some of the smoke detectors were installed in the wrong location.  There is a local code in Providence which the electrician had not done many projects with before and was not completely familiar.  

After the fire inspector left the electrician said he would get me a price for the additional work to change the items which didn't pass.  Am I wrong for thinking I should not have to pay for his mistakes when he originally quoted a complete job and didn't pass due to his own errors?