Has your clients pointed out your mistakes before?

[Btaliat]

There can be a situation where clients point out errors in what the freelancers did. Sometimes, just clients just did this to help the freelancers to get improvement on their skills against next time. Others may do so to get refund. It is always a good thing when a client just pointed it out for the freelancer to get improved. Infact, this doesn't stop some clients in giving such a freelancer good rating. Has it happened to you before?