The documentation states that if the correct password is entered, log in occurs without delay. However, this is not quite true. Take the following situation: A new application is trying to connect to the database but is configured with the wrong password. Typically configured with some connection pooling, this will very quickly reach the 10 second delay. Now, whilst this new application is trying to incorrectly connect to the database, ALL attempts (correct and incorrect) to connect to that database user are delayed. This means existing applications will but delayed even though they have the correct credentials.
I experienced this on 184.108.40.206.0. Let's hope Oracle come up with a fix!