Sorry Little Friend. The research is clear and there is a lot of it. There are measurable correlations between boardroom decisions and rates of critical incidents. Only a fool would deny the connection. But note that I say RATES of critical incidents. The problem is that it is very difficult to attribute any particular critical incident to to any particular board decision. Therefore lots of linear thinkers and incompetent managers can pretend there isn't a connection.
The question is how far good airmanship can reasonably be expected to compensate for poor governance and management.