They may have already done that. But the "ace up the sleeve" I was referring to may just be the mole(s). WMI has kind of hinted that they knew someone from the inside may have helped them out. If that is so, they may have already talked and handed over their(the mole(s)'s) hard evidence to the lawyers. You have to remember, the more people there are involved in something, the more likely it is that one of those people will turn on you and screw up the plan.
So let's say they give selected documents and not all of them. If WMI can prove that just one of the documents they have is true, case closed for JPM and people go to jail. I would wager that not a single person at JPM wants that to happen.
"I really don't see any problems here, as long as I don't have to look at you, talk to you, or smell you." -Christopher Walken