Can you explain the math behind the "Reserve Deficit Sell Penalty" example ? If 1M loses 50k in value (5% loss), then surely someone holding $320 would face a

Can you explain the math behind the "Reserve Deficit Sell Penalty" example ? If 1M loses 50k in value (5% loss), then surely someone holding $320 would face a $16 haircut ? The example shows $2.