When I first gained 500 reputation and did some reviewing, I came across a question that was your typical new-user spam.
I clicked on the link to it and found that it was closed. Not wanting to clutter queues with an issue that had already been resolved - even unsure of what would happen if I flagged a closed question - I clicked on 'No Action Needed'. Then I got the infamous 'audit failed' message.
Surely there should be a warning that some reviews are audits and to always review as you believe you should, even if there seems to be a bug? This warning would be on the privileges page for accessing review queues.