It's a liquid, not a box of stuff.
Nothing was made, nothing was sold, but he fraudulently tracked a creation and sale by creating the RIN.
I "sell" you 10,000 barrels of fuel. Then I give you back 99% of your money. Rinse and repeat, you've generated lots of RINs with little capacity for anyone to catch you downstream. Contrast this with a carbon tax, where in order to legally generate revenue one must pay the tax.
Daniel Yergin covers this in detail in chapter 13 of his truly epic history of oil, The Prize (1992).
https://www.worldcat.org/title/prize-the-epic-quest-for-oil-...
Also:
https://tshaonline.org/handbook/online/articles/mlc03
https://www.law.cornell.edu/uscode/text/15/715f
And a good, concise overview of the history here: http://www.reuters.com/article/2015/01/29/us-usa-crude-stock...
(I'm not sure that there are not some provisions to close these loopholes. https://xkcd.com/1494/ )
I wouldn't go that far. Each RIN needs to correspond to some physical bio-fuel. They were generating RINS but not manufacturing the corresponding fuel. Seems like straight forward fraud. Now had they been actually making the fuel but then dumping it in the trash and just selling the RIN I agree it would be harder to see what it was they were doing wrong but they weren't doing that.