To be fair how much part does the head of any organisation play in making the day to day decisions that the organisation/company has to make?
It is very easy to say afterwards when the fat really hits the fan and someone famous is found to be truly steeped in crime, like Saville, and, possibly, Al Fayed.
But we are a country that prides itself on the rule of law - and that means we have high and clear standards about the quality of evidence that is needed to convict someone and it does neither the reputation of our legal system, nor the people accused, whether they are famous or not, if they get taken to court on evidence that is not sufficient to secure a conviction.
Rumour and stories and a few witnesses, who may at the last minute change their mind about giving evidence, for a number of reasons including fear of reprisals or, alternatively, being bought off, can make cases like this very difficult to bring to court, so failing to take a case to court in the first place, however damning LATER evidence may be is no sign that the first case was caused by failure by the CPS.