Someone demo'd it on a couple new iphones at the hackerspace yesterday. They got to the homescreen with all the app buttons through the clock exploit. It wasn't just access to the dialer. Once you get through to the clock, you can hit the home button and it just hops to the home screen.
I have no idea how this works in regard to the encryption. It isn't likely anyone else here does either. They are just speculating.
I hope that it is good, but I don't trust it. No one should trust it.
I've spent a fair amount of time now trying to reproduce this on iOS 9.02 on a 5s, and I can't make it work. I can easily get to the clock by asking Siri and then tapping the clock in her results, or by swiping up from the bottom of the screen, but either way when I press the home button it dumps me back to the "Enter Your Passcode" screen.
I don't mean this as a claim that the iPhone is a secure device, since it obviously isn't in several different ways, but rather just that I can't reproduce this specific behavior.
How can you do that? Are you sure your not just engaging touch id? I tried it with my thumb, which 'unlocked'. Then I tried again with my fingernail, which didn't unlock it.
If the phone is locked, the decryption keys aren't in memory and your finger or password are required to access them, and no amount of bugs in Siri can get around that.
