When you true to finish setup with a wrong password it takes a few seconds of waiting for the password bar to tell the user. For comparison, if the password is correct it progresses to the next screen almost instaneously.

It could just be that the IPC itself is slow but I don't see why it would be slower for an incorrect password. I suspect that we're not handling the promise from QuickUnlockPrivate.getAuthToken() function the best way when it fails to get the token due to a wrong password.