If my memory serves me right, ActiBlizz is well within its rights to see the evidence being used against them before litigation. Procedural stuff is not my forte, but I think this is the case.
Regardless of innocence or guilt, ActiBlizz would likely respond the same way. One has to keep in mind that even filing such claims are a huge PR issue, even if nothing comes out. Heck, these forums have tons of people ready to instantly condemn ActiBlizz just based upon the accusations, which means the PR damage is already being done. The court filing's introduction is just as accusatory as ActiBlizz's statement, as this is how the game is played.
I think people should always have a healthy bit of skepticism when it comes to matters like these, as it's never just black or white. Personally, I wouldn't put it past the DFEH (as a government body itself) to be embellishing the situation to make it seem way worse than it is. I mean California has never been known to have governmental agencies to overreach or do shady things, right?
That's not to say this suit is one such instance, it may be 100% legit, but it also may not be. This is why you want to let these things play out, as you should not just automatically trust government or large corporations and what they tell you without verification.