If he did not trust Nefario from the beginning, but he resorted to use GLBSE anyway, then he exposed his investors to a third-party risk that he knew about without informing them about it.
Any such risks would have been equally obvious, or non-obvious, to the issuer and to the investors. It's not like some decision on the part of the issuer exposes the investors to this risk in a way that was hidden.
In retrospect, I agree with you. Anyone listing an asset on a stock exchange like GLBSE should have included a section in the offer explaining the risks associated with using an anonymous exchange. And they should also have included a section explaining what would happen if the exchange failed or delisted the asset.
It's hard to blame any specific person for not predicting this because, as far as I know, nobody predicted it. In retrospect, though, it's obvious that it's a significant risk that should have been addressed ahead of time.
It looks like the crypto-currency community is going to have to learn every single painful lesson that the regular financial world has learned. Probably more than once.
Don't try to shift the blame. Nefario has already sent him a list of investors' assets. The jig is up. .
There is nothing to claim. The investors' assets list Nefario sent him should be considered true until the opposite is proven. Otherwise it is too easy for him to steal such assets with such lame argument.
Nobody knows how to do this. If you do, please explain it to me. For example, what happens if someone claims they held the asset but the asset issuer claims they weren't on the list? This could be resolved if GLBSE was actively participating or had made the lists cryptographically verifiable. But so far as I know, there is zero participation from Nefario/GLBSE.