If oil companies were punished more harshly for their spills they would happen much less often. They need to be held accountable, either financially or in some other way, so that they are encouraged to reduce the number of disasters and not simply write them off as the cost of doing business.
Oil companies should consistently and harshly be punished when it comes to oil spills. Their job to transport the oil in the safest possible fashion needs to be taken seriously so harsh and specific punishments even directly aimed at the individual employees should be in place. And as with any investigation, if it is found that the incident that caused the spill was completely out of the company and operators hands, clearly the punishments can be adjusted.
The impact from major oil spills is devastating for the environment and oil companies need to be punished for the damage that they cause. There also needs to be a set of requirements for the clean up and compensation to those who are effected. The oil companies have a great deal of profit from their business and can easily afford to pay for damages.
No amount of preventative measures can ensure that a bad result never happens. The only thing that the oil companies should have to do is take reasonable measures in order to prevent spills. They can't prevent everything, and there is no sense in bankrupting the companies that provide valuable oil and energy to the public.