Could be that JPMorgan traders and others involved never thought for a minute that their trading scheme would ever see the light of day, since it's been going for years, visible but few if any lasting smoking guns, and the CFTC comatose.
Now that the whistle blower's emails to the CFTC have become known, thanks to their ignoring them, maybe this smoking gun will stick.
I suspect that JPM and others know that GATA and their allies have the financial clout to keep this from dying, which JPM may hope will happen anyway eventually. Perhaps they've muzzled their traders until they have an idea where this is going.
No sense for them to keep on with the dirty tricks and provide more proof of what's been going on. And I'll bet none of the blabbermouth traders have been shown the door either for fear they too would then blow the whistle. I doubt their bonuses would even be cut. What a bunch of meatheads.