Actually, in some countries/states/provinces, there are laws that protect AND also can prosecute engineers who are guilty of such offenses. For example, here in Canada, to use the term engineer, means a professional engineer (a P. Eng). It's a protected professional designation bound by various laws and regulations. A large portion of the profession is ethics and the legal requirement to whistle-blow, REGARDLESS of who pays your salary. If you want proof of this, and why this is a good thing, here is an example:
In Ontario, Canada, there was a mechanical or structural engineer (can't remember which) who signed off that a mall parking garage (was built on the roof of the mall, oddly), was in fact structurally safe. Even though there was numerous concerns by tenants and visitors about the safety of the structure, weeks after the engineers last 'pass' inspection, the roof collapsed killing two people. (see story: http://www.cbc.ca/news/canada/...).
The gist is, the engineer knew there was deficiencies and signed off on it anyway. Needless to say, he is facing criminal charges, and likely has had his licence revoked, and his career is over! If you are an engineer in Canada, you can't pull the 'my boss told me to' excuse. I know this because my father worked 35+ years as a licensed electrical engineer in Canada. You tend to pick up on things like this growing up. However, I can't speak about engineering in other countries but I would hope this is the case in the US.