Todd, a few points:
1. It's kind of poor form to tell a disappointed customer that their issue is rare, or that you "didn't have time" to do quality control on the disc you shipped them.
2. It's equally poor form to assume that their issue was small, or dismiss it "a minor dropout in a squiggle"
I teach my employees to "Apologize, Empathize, Offer". Even if the issue isn't your fault, Apologize that the customer's expectations were not met. Show that you understand how let down they were, and offer a solution to make it right.
Your response has made me decide to wait for either of the retailers I usually do business with to restock their selection of Proxys, as opposed to giving Infinite a chance, even though you have a Plasma Proxy and an Atom I like. A response along the lines of "Hey Gdingy, I'm sorry the limited edition disc we sent you didn't meet your expectations. We did not intend to ship out any discs that didn't live up to our high standards, and I'm unhappy we failed you in this regard. Please PM me so I can notate your account and apply a credit of ($5, 10%, free shipping, whatever) to your next purchase." would have been enough to get my to try Infinite. Instead, I'll wait on my local retailer or Community to restock. I'll pay more through either one, but it's worth it for the great customer service I get from them.