When you get a draft from your writer/designer after a change is made, read and review not only the changes but the whole copy, and the design, as well. It’s probable you’ll find a mistake you initially missed.
It’s also possible that the designer didn’t make the changes that you requested as you requested them, so be sure to check. Each time you make changes, you need to review a proof before it goes to press/is uploaded. It’s your responsibility to make sure it’s perfect, not the designer’s.
I’m being stern here, and I need to be. Each time there’s changes it costs everybody time, energy and money. Save yourself a lot of time by making sure the first proof and then the 2nd and hopefully last proof are correct.
And proofing your proofs?
Find somebody who can spot a mistake from the Hubble Telescope.