I (and probably many other people) have accidentally clicked the wrong button in reviews. For example, I just clicked the Leave Open button when I wanted to click Close. I think many people have done this. I think an ability to undo this would be appreciated.
Destructive actions (close, delete, flag) already have a confirmation that you'll need to click through before proceeding. Editing requires you to actually make changes before submitting. This leaves various "it's ok" responses. While it's certainly unfortunate if you click these when there's an actual problem with the post, it's not exactly critical that you be able to change this response either; if there's a problem, someone else will catch it eventually.
Note that "undo" is tricky in all cases, even the relatively benign "do nothing" ones: if the review has completed, and particularly if significant time has passed since it completed, changing your response may not be possible.
I think the cost of this outweighs the advantages at this point.
We could have a button next to the post in the activity->reviews listing in the user profile. It would need to exist depending on the queue type, and the status of the post.
- Closed Votes - If closed then no button.
- Suggested Edit - If edit has already been a approved then no button.
- First Posts - If approved then no button.
- Late Answers - If approved then no button.
- Low Quality Posts - If approved or deleted then no button.
- Reopen Votes - If reopened then no button.
Note, that I'm not sure of the complete workflow for the First, Late and Low queues, i.e. whether it takes multiple users to take them out of the queue or not.
If any of these have been completed so that the button doesn't exist, then they can click on the post link and maybe do something (though they would have already used their close/reopen votes in those queues).