Grenville agreed to facilitate transfers of funds from a Taiwanese businessman who he did not know. Grenville was to deposit cheques in his account and forward the funds to Asian accounts in exchange for a 5% commission. Without Grenville’s knowledge, the first cheque (in the amount of $10 000) that he deposited in his credit union account had been altered and forged. Several months after the cheque cleared, the defects in the cheque were discovered. Grenville’s credit union took the full balance in Grenville’s account ($6000) and sued him for the remaining $4000. Is the credit union entitled to recover the $10 000 from Grenville? What are the relevant rules?