Does missing iPhone 5s fingerprint data pose security threat?

If my iPhone 5s fingerprint data is walled off from the rest of A7 chip and the rest of iOS 7 in a 'Secure Enclave' and is never accessed by iOS or other apps, as Apple claims, then how come it all vanished when my iPhone crashed and I had to go through the entire fingerprint scan registration process again? Apple is remaining very quiet about it...