No county, municipal, or school official may participate in discussing or vote on any issue in which the official has a conflict of interest. Each official shall decide if any potential conflict of interest requires such official to be disqualified from participating in discussion or voting. However, no such official may participate in discussing or vote on an issue if the following circumstances apply:
If an official with a direct pecuniary interest participates in discussion or votes on a matter before the governing body, the legal sole remedy is to invalidate that official's vote.
SDCL 6-1-17