A spike on mtgox doesnt show that nefario has sold coins   why is this even relevant?

a transaction ID that links a BTC transaction to the GLBSE just before closing would be incriminating.

however the person making this claim has in the same post as he made the claim admitted that it is fine to jump to his own concllusions with no evidence therefore IMO weaking his own allegations. If he is going to make allegations such as this after discrediting himself he should need to provide evidence if he is to be taken seriously.