There should be a way to undo a recent change to your build without respeccing or retiring if you do it within 5 to 10 minutes or so, because i mean if you accidentally put the wrong stat in something, then hit save without realizing it, you shouldnt really have to wait 8 million xp or lose half of your current xp to fix it. Its different from respeccing because you wouldnt be able to change your build entirely to something else, but just a short timeframe to undo recent changes. I realize this is kinda what the "save" button is for, but many times people instinctively click that without reviewing their changes. Its basically the same concept as how you can apply for a namechange to fix a typo, except id say your build is a bit more important than a typo..