I don't know what the court will say, but they could say that the people were trading non-existent coins, so the balances are meaningless.

Actual deposits and withdrawals are numbers that the court can verify with the banks and in the blockchain.  The trades inside MtGOX are recorded only in Mark's database, and any information that comes from him must be treated as a mere hint that needs independent evidence to be trusted.  The database may have been doctored to give large bogus balances to some clients.