Retained without being stored? too Zen for me ;)
The actual words from the announcement are
"fingerprints are not stored and are automatically deleted from the device once they have been checked"
Odd how the article (and many other reports) omitted the "are not stored".
And yes, you can argue that it's a lie and they will be stored after all. After all, none of the many people who would have to be privy to that would leak the fact, would they?