In what way? For the Vanimedle player to make these claims without violation of the social Contract he must have evidence of absence. That is, he must have evidence that the secession in question was planned with little to no IC interaction, which is certainly provable (and also falsifiable).
And I and several others can provide significant evidence that it
was planned IC. I can't guarantee that there were no OOC discussions, but a
lot of planning was certainly done IC, and I think that makes the accusation pretty baseless.
Also, I think the burden of proof has to be with the accuser in these cases. If you're going to make a public accusation, you damn well better include the evidence, other wise it's a violation.