The games sent to testers etc are unreleased and valuable intellectual property (IP) products.

Pre-release surely the thing to do would be to host a cloud service like On Live?
These do not give access to the files but give complete control of the game. Even then you would have to trust the host I guess, unless they could host it themselves.
As last time(Crysis 2) the files were released early via file sharing sites.

Guess Crytek/EA will have to be more careful this time.

I'll still be looking out for stray video footage before the release of Crysis 3 to help make my buying decision.