(a) If, without the fault of the lessee, lessor or supplier, agreed berthing, loading or unloading facilities or an agreed type of carrier becomes unavailable, or an agreed manner of delivery otherwise becomes commercially impracticable, a party may claim excuse under § 42a-2A-605 unless a commercially reasonable substitute is available. In such case, reasonable substitute performance must be tendered and accepted.

(b) If an agreed means or manner of payment fails because of domestic or foreign governmental statute, regulation or order, the lessor may withhold or stop delivery, or cause the supplier to withhold or stop delivery, until the lessee provides a means or manner of payment which is commercially a substantial equivalent. If delivery has already been made, payment by the means or in the manner provided by such statute, regulation or order discharges the lessee’s obligation unless such statute, regulation or order is discriminatory, oppressive or predatory.