To me, nubbins did an actual PSA, converting his free time to a public warning. Nubbins did the right thing. I think we need more people like him in this community. We all have some special knowledge on different topics. Sharing it will help the community in its entirety.
Now on this specific case, I think the evidence presented was quite convincing. You can't really say that it was a baseless accusation. Bitcointalk seems to have pretty decent understanding of who is a bad guy and who is not. This community usually comes to the right conclusion when appropriate evidence is presented.
If Nubbins had simply presented his suspicions and left it at that I might be willing to agree he is providing a service. Instead he decided it was appropriate to turn it into a personal matter by going around negging WC before he even had an opportunity to respond, and also attempted to intimidate others into not speaking out about it by leaving negative trust ratings for anyone who disagreed with his accusations. This is destructive, not productive, and completely relies on the fact that Nubbin's suspicions are correct, something that an impartial person doesn't do before all the evidence is presented. .
It is clear that for whatever reason, be it to harm the reputation of competition, or just to entertain himself, Nubbins has clear intent to damage the reputation of WC and anyone else who agrees with him.
What evidence EXACTLY was quite convincing? Because I don't see any evidence, just a bunch of people speculating about what COULD have happened and ignoring perfectly logical explanations with contrary evidence. The fact that he didn't make a video that satisfied the peanut gallery is just evidence of poor video making skills, not evidence of his guilt. This again is just another suspicion.