R19 in 3 year old Florida Home

I did an ispection yesterday where the ceiling insulation is R19 (maybe less) using loose Cellulose. I have looked at the IRC code and it specifies R30 for Zone 2. Are there exceptions to this rule? http://ahipros.com/insulationr19.JPG

I used the manufacture’s chart for depth, which corresponded to what was posted.

I just got off the phone with the Orange County Building inspector and he states that R19-R30 can be exceptable depending on how the home’s energy efficiencies were calculated when the home is designed. He further stated that if he sees R19, he must pull out the design plans and verify that R19 was the design spec. In addition, he states that if he sees R30, he does not need to check further, because R30 and above always meets the spec.