What causes ethical meltdowns?

I am reading Menzel again. The article published in Public Inetgrity (2009, 11:4) titled "I didn't do anything unethical, illegal or Immoral" is a case study of eruption of ethical problems in one American county. A very interesting article.

The story in a nutshell goes like this: an elected official - a property appraiser - has had a steady seat for over two decades. Private property he'd been trying to sell for months is not selling and was now in rush to get the money, after divorcing his wife. He suddenly decides to be very unhappy because the hurricane flood repairs had caused damage to his property in 2004. He tells about the damage to the county administrator, also a highly experienced public servant, and he promises to look into the matter.

After a while, without consulting outside experts on the value, the county buys the property from the appraiser. A long story short: the media finds out and public is furious. The county attorney gets the boot in the aftermath. The appraiser resigns. There are some more juicy details in the story but I recommend reading the article. 

How is it possible that long-term elected and appointed officials seem suddenly have forgotten what is ethical and what is not?  How come these types of situations are not recognized to begin with? What causes ethical meltdowns?

According to the article there always seems to be 

1. A trigger event. An event that reveals the wrongdoing and makes unethical behaviour public.
   
2. Fragmented nature of local governance. Lots of elected and appointed people with certain amount of independence. Who is accountable for institutional unethicalness? 
3. (Too) Long careers. People become too comfortable with each other and good intentions might go bad. 
4. Lack of healthy skepticism towards colleagues (due to circle of trust).
   

And in order to build and restore the public trust

1. All of the officials who are responsible of the unethical behaviour/ scandal should be removed from office.
2. Term limits for the county commissioners. 
   
3. Joint code of ethics for all officials (with credible enforcement mechanism AND appearance standard = officials avoid even the appearance of unethical behaviour). 
4. Decision-making transparency and due diligence. Plain and simple. 
   

I would love to hear some comments from Finnish municipalities on this one. How are you making sure that unethical decision-making is not happening as we speak? Where are your ethical blind spots? 

MV