If you review a post in the First Posts or Late Answers review queues, and you have already edited/voted on/commented on it, the item will already have the 'I'm Done' button enabled. Usually, the 'No Action Needed' button is disabled in those cases, but (in my experience) since 6-8 weeks, in 20%-40% of the times, it is not. See the screenshot below for an example:
I couldn't detect any pattern between the specific actions I've already taken on the post and whether the No Action Needed button is enabled or not.
This post from 2012 is similar, but I'm pretty sure that request was already implemented and (as far as I know) it used to work correctly until a few months ago.