Q:

This question has a reason to be asked: Why isn't this question a duplicate?

Addendum / Preface
I did not get any response to this question, so I will explain why I'm asking: at some point yesterday evening I hit the 3K rep mark in SO: that means that now I have the power to vote to close questions. Voting is not flagging: I believe it's a much bigger responsibility. I'm not just saying: "hey, could you please take a look at this question? I believe it should be closed" anymore; now, I'm saying: "Let's close it". In light of this new responsibility, I want to make sure I understand what determines when a question is a duplicate or not. Most of the cases will be easy, obvious ones, and I'm not interested in those. This one below, on the contrary, does not seem obvious to me and thus I would appreciate your comments. This is not a question about "give me those 10 points back!". My flag weight is high enough and I could not care less for 10 more points in there.
Original question below:

This question: Android Development Environment Linux is about installing the Android SDK on a computer without Internet access. The fact that it's running Linux is completely irrelevant to the problem.
So, I linked this other question in a comment: Download the Android SDK components for offline install and flagged the question as a duplicate. The original asker even thanked me for the link in there.
Why was it not then closed as a dupe?
The accepted answer (by TheTXI)) to the question: When is a duplicate question not a duplicate? proposes: "Rule of thumb: If you ask a question similar to another question and it is likely to get the exact same answer, you have yourself a duplicate question." and that is clearly happening here.
PS: If you see the time at which I flagged the question, you will notice it was after the asker thanked me for the link and thus I confirmed that it was the same problem.

A:

If you have close voting privileges, just vote it. If other 4 users with close vote privileges agree, they will also vote on it. If nobody agree, your vote will go away after few days later.
But if you flag it for moderator attention to close it, the decision is by only you and a moderator.
Moderator or other close voters may think that, 

that question has better answer than old one
or they may think that merging is better instead of closing as duplicate
the other post is on Windows XP, and this one is Linux, so they don't want to close it as duplicate just because of personal preferences.
and there is a lot of posts like that, they may ignore just for this case

May be there is many mores that I am not seeing also ...
You just need to move on, instead of just sticking on one post, I think.

