One of the things I teach in our admin course is that it's not enough to just be the gatekeeper/central point of change when it comes to being a DBA, we should be adding value:
You'll notice that I don't put in the list verifying the change is correct - that's a QA task!
One sub bullet point I've added to 'is it stupid' recently is checking queries for unused tables. I ran across a couple instances lately of what was probably copy/paste code reuse and I was tuning the queries, realized that several tables were included that had no effect on the results. Easy to miss something when you see things like this so it definitely needs to go back for testing, but it's worth taking the deeper look right then, before you deploy.