Theres plenty of blame to go around. But if this guy stayed within limits and everything documented, what did he have to lose? He has his bundle from last year, so he can retire and never work again.
If the trade had gone his way, the fund size doubles in a month, hes a hero with potentially a 250 million+ bonus. If Natty had gone to 15 or 20, the folks who end up ultimately paying his bonus are folks who use NG to heat their homes or run a business.
His trade failed, he has nothing to lose and he reitres. The incentive to this firm/trader was wrong. This is kind of why some larger firms will grant options/stock that vests through time, so traders dont bet the ranch and walk away if it fails.
This type of trading will ultimately create much greater problems as a regulator or legislator can say, with some real gravity, that these markets require real supervision and investigation.
It'll also be interesting to see if any of the sellers were NG producers who intend to deliver against their sale. The earnings will be curious