1. Needs to help ASAP on correcting the data problems on the production instance, 2. Development be trained on how to properly design tables, etc., or 3. Development has their "Create Table", etc. privs taken away, so only a "knowledgable" person can create the data structure, relegating the dev team to purely application development, not data development.
A post with sound advice on fixing the problem.
-- Jared Still Certifiable Oracle DBA and Part Time Perl Evangelist