I was reviewing questions from new users.

So, I got well known, one time Stack Exchange network hot question about broken RJ-45 plug presented to me as question from new user. My instant though was - this is duplicate! I even was surprised that this new person put exactly same picture in his question. Without even thinking I pressed flag to attract moderator's attention.

Well, after that a banner appeared informing me that I need to stop and listen and that my review was inappropriate.

I know it was high quality question and I would accept it otherwise if it would not be a duplicate.

What is correct way of handling these questions?

Should this testing behavior be fixed and allow reviewer to mark it as duplicate and pass the test?

EDIT

There are share, edit and flag options available to me.

Here is a screenshot of what I see when I review questions: