We can use a legal analogy to decide whether Scar got 5th at GENESIS. Scar's general argument has been that the tournament format that Genesis used was illegitimate.

When you sue someone who's out of state, you can't always make them show up to court. If I sued Scar in Minnesota for punching me at Big House 5, Scar could just say, "I'm not going to court in Minnesota because that court doesn't have any power over me." (Note: Scar did not punch me at Big House 5.) In that case, the court doesn't have "jurisdiction" over Scar.

BUT, if I sue Scar in Minnesota, and he comes to Minnesota and says that he didn't punch me, he can't make the argument that the court doesn't have jurisdiction over him or that the court proceedings were illegitimate. He waived the right to object to the court's power by showing up and making legal arguments about the case. It would be unfair to allow Scar to try to argue that he didn't punch me and then, if he lost, to later claim the whole trial wasn't legal.

In the same way, Scar waived his right to contest the legitimacy of Genesis's tournament format by showing up to his 5th/6th place match against Mew2king. Because of basic principles of fairness, he cannot attempt to beat M2k and then to claim 5th place after losing the match.