Proceeds from the sale of the stock go to the liquidator to distribute amongst the general body of creditors including the bank.The bank would not have been entitled to take 100% of the proceeds from the sale of stock in any event.
It sounds like your partner had to pay off the bank under a guarantee and if you were a joint guarantor he is suing you for your share of the shortfall to the bank that he had to pay
If he took the stock as you say then you should notify the liquidator and let them take action. It won't improve the Bank situation. As a shareholder you must have been aware that the business was going into liquidation as it's put to a vote,why didn't you mention it at the time?