I think I have found a bug. I was reviewing "late answers" on Stack Overflow. I've clicked the show comments button, on the original question, and immediately after that I got a message, that it was only a test, and I passed. Shouldn't I pass the test only AFTER I made some action?
This was only a test, designed to make sure you were paying attention. You passed.
Review audits are made for finding robo-reviewers who are not paying any attention to the review posts by just clicking on the No action needed button to increase their review count/ for gaining badges.
By clicking on the Add/Show comments button, you were paying attention to the review. This could also be considered as an action for a review audit.