An incident occured where many completely uninvolved people were killed or injured away from the air display area. There were a combination of factors that ultimately led to this tragedy, but the primary factor has to be that the pilot misjudged the maneouvre.
A large number of people had their lives irrevokably changed that day as a result of an incident that should have been avoidable. Whether criminal proceedings take place, or not, is a matter for the judiciary. What penalties might be imposed are again a matter for the judiciary. I am merely pointing out that the sentences imposed by our courts frequently do not directly reflect the case being considered but are intended to act as a deterrent to others who might be tempted to act in a similar manner, or avoid their responsibilities towards public safety. I would suggest corporate manslaughter charges are a distinct possibility in this particular incident.
I make no judgement as to the potential outcome but clearly there is a public demand that a price and compensation for the victims be paid. For that to happen, someone will have to be held responsible.