Fulton County and Fulton County Schools sat out on a case that could have cost them a combined $1.5 million in tax collections.
Representatives for the county and school district chose not to participate in a 2016 court battle waged by Alpharetta against North American Properties, owners of Avalon.
The mega-development filed an appeal in February 2016 claiming that its 2015 tax assessment was too high.
It sought reimbursement from the county, the school district and the city for a majority of the $2.3 million it had paid in property taxes claiming its property was assessed improperly.
Avalon argued that the development was not issued a certificate of occupation until after Jan. 1, 2015, and, therefore, the property should be valued based on its pre-development status.