Okay....I played with this some more, and I found that Siri will work at times. It is very infrequent, but she can transfer from taking the call command to actually placing the call at times. Each time the 4s transitions from Siri to the phone call screen, the "phone call was disconnected" message appears on the Z2. I'm not sure if it happens to transition faster at times, but there are instances where the Z2 is capable of making a voice call with Siri.