If it is negotiated, it is equivalent to the authorization of the parties themselves. The counterpart of the contract can urge the client, that is, the director you mentioned, to ratify it within one month. If the trustor fails to declare it, it shall be deemed as refusal to ratify it. Before the contract is ratified, the counterpart of the bona fide contract has the right to cancel the contract. Revocation shall be made by notice.
According to the specific circumstances of your case, if he agrees to sign on his behalf, it means that he has ratified it and admitted that his signature is his own. Then, if the contract is recognized by the other party, failure to perform the contract means that he has breached the contract. If he refuses to admit that it was inspired by him and says that it was signed by employees, I'm afraid it will be difficult to prove it.