Some engineers at the "top" are the least ethical.
I recently retired from a career in consulting civil engineering that I found very disappointing because of the unethical "politicking" that is widely practised by firms in obtaining contracts -- particularly when those are "no bid" contracts from government agencies. The most blatant example of this is in the form of large contributions to the political campaigns of politicians responsible for hiring consultants, but there are many more subtle but equally pernicious ways of subverting the ideal of professional objectivity and competence being the basis for the award of contracts.
At least in this particular branch of civil engineering, there is an "adverse selection" process at work whereby the engineers who are the most willing to ignore ethical standards (and the most adept at not getting caught) are the ones who rise to top managerial positions. About the only legal restraints on unethical conduct are contained in Codes of Conduct that are administered by state boards of professional practice. But it is a classic case of the fox guarding the henhouse, because these boards are typically composed of "prominent" engineers and architects who are appointed by state governors based on their self-serving political activism. These boards typically take action against "little guys" such as small contractors who build something without hiring an engineer or architect, but are only interested in investigating the activities of "prominent" firms when their lack of professionalism causes a major failure of some facility that they have designed.