If it's actually that bad, you should just fire them or do your best to not work with them because they will drag you down with them. For milder/more moderate

If it's actually that bad, you should just fire them or do your best to not work with them because they will drag you down with them. For milder/more moderate cases, giving someone a way to concede without publicly admitting they're wrong is a often a useful tactic to get said person to do things the right way while building trust in your relationship with them.