There is also the question of what should count as the claim of a client against MtGOX: (1) the account balance he had at some point before the final shutdown (when, exactly?) according to MtGOX's internal ledgers, or (2) the total amount he deposited, minus the total amount he withdrew? It is known which approach the liquidators will follow?
Approach (2) is the standard in US law. This was a big deal in the Madoff case, because there were lots of Madoff customers with huge account balances representing Madoff trades that never happened. But Madoff customers are being paid off based on actual deposits minus withdrawals, ignoring fictitious gains.
There main difference between this case and Madoff, is that the trades actually happened, and people were making their own trading decisions.
Several poker sites have gone bankrupt over the years. How were their creditors paid back? Did players who lost all their money years ago get their deposits back, leaving nothing to those who gained their money from paying well, or was their final balance used to calculate their claims?