Add an "oops!" so skimmers don't mistake the bad example for a good one

content/blog/2018-05-23-react-v-16-4.md

@@ -52,7 +52,7 @@ static getDerivedStateFromProps(props, state) {
     return {
       // Since this method fires on both props and state changes, local updates
       // to the controlled value will be ignored, since the props version always
-      // overrides it.
+      // overrides it. Oops!
       controlledValue: props.value,
     };
   }