First of all I know this is a super small bug, but it's still a bug (in my opinion, anyway). When you nominate to re-open a closed question, the link to re-open stays there and if you click it a second time, the same dialog appears as if it is going to let to do it again (but of course doesn't let you).
Normally, I would ignore small things like this. However, I think this kinda makes StackExchange sites appear a little funky. In a way, it (sorta) makes it look bad. I myself have to laugh at this, and I'm sure others have also laughed at it.
The point is, it shouldn't even allow you to press this link again in the first place. Or at least don't show the same dialog asking if you're sure you want to nominate to re-open. Just immediately alert the user that they already nominated.
That is all.