Anom
At any stage, the MMs will be short/long merely as a by product of doing business - do you believe they are liable for settlement regardless of the situation?
Are those who sold but the registrtaions may not have completed liable to take back their worthless shares and refund the MMs? What you are suggesting is that at any stage if you hold a stock that has down, you can approach your broker and if settlement has not been completed get your money back.
Was there an obiter with the Room Service decision?