My speculation is that it maybe tries to crack the hashed value and input that to the phone instead, rather than interfacing with the password screen.
in other words: the encryption/wipe code may be a function of the password screen, but the phone may accept a hashed key as a valid unlock attempt through a different interface that does not contribute to the failed attempts limit.
in other words: the encryption/wipe code may be a function of the password screen, but the phone may accept a hashed key as a valid unlock attempt through a different interface that does not contribute to the failed attempts limit.