Of course you can still recover your phone by flashing the latest KitKat firmware but what we're aiming for here is to flash the old Jelly Bean. According to some people's reports that have tried downgrading, they end up with an error message when attempting to flash even the last Jelly Bean build released.
Just recently, a few users from xda forums reported that there is one particular firmware that manages to flash succesfully on the phone. This particular firmware comes from Brazil with PDA I9195UBUBNE2. Apparently it has the new KNOX swrev2 bootloader and that might be the reason it is able to flash onto the phone without any issues.
So if you desperately want to revert back to Jelly Bean, then click here to download the firmware. If you encounter any other firmware builds that manage to flash over KitKat then you may leave a comment for the rest of the viewers to see.