Possibly there is. This is a guess, but by making the raw transaction known it could allow someone to alter the DER encoding of the signature scripts producing a clone of the transaction with different hash. If the modified transaction is then broadcast and confirms before the original Mt.gox may check the original transaction hash and see the outpoints have been double spent then resend the payment using new inputs resulting in the withdrawal been paid twice. It really depends on how Mt.gox detects a failed transaction.