[r00fus]

Given that YT link ist im Deutsch I'm going to pass on decyphering it.

How does registering and unlocking another phone show that it would work on her phone?

I really don't think TouchID is at all riskier than even a 6-digit passcode. I really still wish Apple allowed multi-factor unlocking though.

[acdha]

That’s the English translation but, yes, recovering a fingerprint which can be used to unlock a test device doesn’t show it can replace the original. It’s prudent to assume that the attacks will get better but I think this really highlights the difference between broad and targeted attacks since so many people are better off with the fingerprint unlock.