Cheating RAZER Silver? Abuse Authority? Unsportsmanlike Behavior? Or Back-stabbing?

Please read carefully and commend:

There is a tournament, prize pooled with RAZER Silver.
1st 4000 RAZER Silver
2nd 2000 RAZER Silver
3rd & 4th 1000 RAZER Silver each
5th to 8th 500 RAZER Silver each

This tournament is FOC. And it always consisted constant gamer: A,B,C,D,E and F. (only sometimes will add upto 16 players) Obviously, everyone no matter win or lose, will receive the prizes, only different in amount.

D is not familiar with this game. However, he saw the chances to get RAZER Silver. So he participated for the prize. He downloaded the game, and registered for the game, and played. Every time as long as the tournament consisted only A,B,C,E and F, he most of the time win B,C,E and F. However, he never win player A.

Thus, he thought: “Since this game is not my main, and I don’t care win rate, why not just let it go? And I am satisfying the prize in the placement” For this, every time when he face against player A, he forfeit without playing a game.

The time goes until one admin comes, named XuXX. He realized that player D always forfeit when faced against player A without playing a game. With this as a reason, he penalty Player A. He might think this is an “Unsportsmanlike Behavior”

In this case, if this can be considered "Unsportsmanlike Behavior", then what is the different of:
1. Register a game> report own self lose without playing a game
2. Register a game> Playing game> AFK in game to get lose
3. Register a game> Playing game> playing and pretending to win
4. Register a game> Playing game> playing against a familiar player, in this case player A> lose in the end

If option 4 is the only right, please commend how to judge option 3?

Also, if option 1 and 2 is not allowed, what if the connection lag caused option 2 to be happened?

Please be rational in answering the question. Obviously there is no difference between them. Because in the end, it still lose!

If still really panic for option 4 -- there will never have fine line between "Pretending to win" and "Lose because not skillful"

Lastly, Player A might never report the problem. Because it’s free win!

Or, perhaps Player A had reported this problem. This might little chance he doing so because:
1. As above mentioned, it’s free win!
2. He will always win more RAZER Silver than player D
3. He get win rate increased for free too
4. He get rank up also

Or if wrong is wrong. He reported this case, and “Unsportsmanlike Behavior” established, player D get penalty, but player A still receive RAZER Silver! But look, In this case, don’t you guys think he was back-stabbing Player D?

After all, hope you guys commend for this. Who is right? What should they do? Player A, Player D or the Tournament System?

Quite heavy discussion, but is all about Ideological and moral cultivation and legal basis.