Most people are good and will do the right thing in ordinary times.
Meanwhile, most people will compromise their standards given enough pressure to do so. To expect something different is foolish.
We must be able to hold these two seemingly contradictory ideas in our mind at all times – when we write our policies, create our training, implement our controls, conduct our investigations and when we hire, compensate, promote and discipline.
And we must accept responsibility when things go wrong. Either we failed to properly guard against them or we foolishly expected them not to happen.