(a) Where the contract requires payment before inspection nonconformity of the goods does not excuse the buyer from so making payment unless
(1) the nonconformity appears without inspection; or
(2) despite tender of the required documents the circumstances would justify injunction against honor under this chapter (G.S. 25-5-109(b)).
(b) Payment pursuant to subsection (a) [of this section] does not constitute an acceptance of goods or impair the buyer's right to inspect or any of his remedies.