No you are wrong
[Corporations] are free associations of individuals pooling their capital. On the purely free market, such individuals would simply announce to their creditors that their liability is limited to the capital specifically invested in the corporation, and that beyond this their personal funds are not liable for debts, as they would be under a partnership arrangement. It then rests with the sellers and lenders to this corporation to decide whether or not they will transact business with it. If they do, then they proceed at their own risk.
Your liability contract is not with the other partners/members of BitcoinGlobal, your liability contract was with the users of GLBSE. Since you made no contract saying you have limited liability you have unlimited liability, full liability for the debt. You might have a ~2.5% stake, then you can be held liable for 2.5% of the debt BitcoinGlobal owes to its users if Nefario's payback plan fails.
I guess I disagree with Rothbard. It doesn't make sense to me for someone to be liable for something he didn't personally do unless this state of affairs is changed through contracts. Why should one certain type of contract have the implicit meaning that one side of the contract takes some liability from the other side?