I guess I have never heard of a "case" where someone was punished for that, haynewp.
I agree generally with your August 24 post - I sat on our cities structural committee charged with reviewing and adopting the IBC 2000. Our city/metro area is about 650,000 in population.
During our meetings we were aware of, and looked at the first supplement to the IBC that had just been published, but didn't want to complicate matters....supplements and new codes are coming out like bullets from a machine gun. You have to select a code, review it and adopt it at some point.
We put together a list of amendments to the IBC 2000 that were unique to our region and city and then issued a formal document that was voted on by the city council. This is the document used by our Public Works Department in reviewing plans for permitting. They do not use supplements, they do not use the "latest" spec or code that is not referenced by the IBC. They use what was adopted formally and legally.
But as an engineer, I do agree with MrStohler that I am charged first and formost with the public safety and welfare and that I should keep up with latest developments. After the Northridge earthquake, some of the AISC seismic provisions were deemed to be non-conservative and as an engineer, it would be prudent and proper for me to be wary of using them.