All right a conscientious bike shop guy, without even a gratuitous plug for your own shop. If I lived in Irving it'd be sure to patronize your shop.

The customer is always right, even if he's wrong. Just be sure your polite in pointing out the error of his ways so he doesn't blame you later when he hobbles back in. Got an exchange policy (instore credit only) ready to go? He's hooked now, don't let him get away.