Dec 14Q.2 C - inter company transactions

Hi Sir, Part of the BPP answer re the $50m is that if the $50m is because the goods were sold at a markup of $30m then the inventory can continue to be recognised at $50m, but the payable must also be $50m. Why is the ans saying that inventory can continue to be recognised at $50m if it is sold? Shouldn’t the $20m be deducted from inventory and debited to costs of goods sold and also receivables debited by $50m and revenue credited by $50m if this was the case?