> If we see a pattern of mistakes being made then we can talk about taking steps to prevent them.

...but that's not really nothing? You're acknowledging the error, and saying the action is going to be watch for a repeat, and if there is one in a short-ish amount of time, then you'll move to mitigation. From a human standpoint alone, I know if I was the client in the situation, I'd be a lot happier hearing someone say this instead of a blanket 'nothing'.

Don't get me wrong; I agree with your assessment. But don't sell non-technical actions short!