I don't think it failed, it just said you had to use passcode on first login after restart, just like the touchID
This indicates an error. When you have too many failed Touch ID attempts, the iPhone says "Your passcode is required to enable Touch ID"
After you restart your phone, the message is "Touch ID requires your passcode when iPhone restarts"
Something similar comes up on reboot for touch ID users. You have to enter your passcode once on startup to decrypt the storage where the fingerprint data is stored.
(it asks for your pin)