Memory loss

How is it a non sequitar? The premise for both examples is: There is a situation where unfairness occurs because someone issued it. Conclusion: The casualty will get upset at both the direct cause and the issuer, not just at the issuer.

If the replay was unfair, then them accepting it is not morally right (as opposed to immoral or morally wrong). In other words, it's not the best decision they could make in terms of right and wrong. And there are strong suggestions that XSET players don't think the ruling was fair given their game knowledge and Tweets.

Okay, fair enough.
Let's suppose the issuer compelled the puncher, instead of $500, he threatened to leak out his nudes or spread rumors. Either way, you, who got punched, still have the right to get upset and bitter at the guy who punched you. The morally just thing to do would STILL be for the puncher to tackle on the person with authority, although it's definitely difficult to. The only argument that I see plausible is that it's probably less pressuring for FPX to take the high road, but that doesn't mean XSET is all of a sudden the victim lol. FPX has every right to be upset just as XSET had every right to do the replay. It's strange that you are removing any responsibility because there is an authority figure behind that person. Yes, compulsion removes SOME responsibility, but not ALL (just consider a regular soldier during Nazi Germany).

You say that FPX is justified in their actions

First, I didn't mention any actions; I was talking about their attitude. Saltiness/being salty is a state of being. Not an action. An important distinction. Second, you didn't read what I said in full context. Here is the full context:

Just like almost everyone is going to take the rematch for an opportunity at $1mil even if the decision to replay is unfair, almost everyone is going to be salty toward both the organizers and opponents if they won and have to replay their round 1-2 hours after celebrating. All in all, FPX being salty is wholly justified and there is absolutely no justification for why XSET should be taking the moral high ground here.

Admittedly, the usage of "justifiable" is a little awkward with hindsight, but the point still gets across. If it doesn't, you can just omit what I said for what I said in my prior response.

If you meant that FPX is in the wrong

Do you think XSET taking the rematch is considered wrong? I don't think either is wrong and that they're just in the same category. You may think otherwise, but all I'm saying is that FPX's action was not right in the same likeness that XSET's action was not right.

Legally it would technically constitute libel but you understand what I mean.

That wasn't the point I was making, although there is also that distinction; the point I was making is that legally you'd need to implicate wrongful intention for either slanderous or libelous remarks. Of which, what Zyppan tweeted can be considered an honest mistake regarding the information available of a public figure/entity, and would not be ruled in the American court of law as either libelous or slanderous, especially since he did not double down on his statements after it was corrected.