After five failed fingerprint attempts, your password is required to unlock the phone. That seems pretty safe to me. If you're ever ordered to unlock the phone, just touch an unregistered finger to it. Fingerprint sensors aren't foolproof. It'd be hard to prove you deliberately sabotaged the effort.
Though, one feature I'd like would be to register a distress fingerprint. Then I could touch say... my left index finger to require a password unlock.
Though, one feature I'd like would be to register a distress fingerprint. Then I could touch say... my left index finger to require a password unlock.