Judges don’t make decisions on “knowledge.” No one can be expected to know all laws, and keep up to date on how they may have changed by Court decisions. They have staffs that do research, and both sides in the case will submit and make researched legal arguments.
Companies can’t “prosecute” that’s for criminal cases that have to brought by a governmental agency. They can file civil suits, but to get past initial pleadings they are going to have to allege (and later prove) that they incurred some damages.
Do you have a cite for this case? It sounds questionable. Giving it the most favorable benefit of a doubt, the vessel operator might have filed a civil suit and had it dismissed because they did not suffer damages. But it would be hard to imagine any attorney filing a suit when the client didn’t suffer damages.