Good lord... The companies here are dirty, but lets not forget the EPA for creating the problem in the first place!
What problem did the EPA create exactly? They created a rule that the company disagreed with? That does not give them a right to break it. That's not how the law works.
Someone at Bioversal Trading was clever enough to realize that they could make more money gaming this regulation then actually selling their cargo. Therefore, they ran the train back and forth a dozen times and wracked up money from the Government.
Dirty? Yeah. Fraudulent? Potentially, depending on how the regulation was written.
If anything, it speaks to the danger of hidden incentives in otherwise innocent-looking regulations.