If he did not commit any offences, then I don't know why we are spending time and space talking about him unless it is to close certain loopholes that allow traders to do what he did.
He clearly broke the law, but what's hard to credit is that he was responsible for the flash crash. Seems more likely he was the most inept at covering his tracks and has no decent legal team to fend off the regulators. Of course, the focus on this small fry also lays a smokescreen over the activities of the bigger fish and allows them to tell new clients not to worry, it was just an isolated and bitter rogue individual.
The financial markets have to be dependable and transparent or else people will simply take their money out and the whole thing decays. Regulators should look to their own failings that set up the 2008 crash to realise how crucial their role is to global well-being.