Lots of differing opinions on this. Perhaps depending on whether you are more of a buyer or a seller? And the seller did offer to accept the return, but not cover the shipping cost. So I could have returned it. And probably a lot of people will say I'm an insufficiently_thoughtful_person for not doing so. But as I stated before, I'd prefer to offer it back up via auction and hope someone feels like they received a good deal than get $6 back after return shipping. I mean, regardless of whether I got a fair price at the actual grade, that's not the grade I wanted. But, as they say, opinions are like a**holes. Everybody has one.
That said, I did still feel guilty about the negative feedback. So I sent this to the seller earlier this evening:
I personally still feel your listing was misleading. At best. But I posted this question on a comic forum and opinions were split. Much like my comic book spine. Anyway, I've never left negative feedback before and I don't want to be the one responsible for ruining your 100% positive feedback.
"When a buyer posts negative Feedback accidentally, you can ask them to change it using the Request Feedback Revision page. If there is no response from the buyer, you can go to the Report Feedback page and explain the situation directly to eBay so they can handle the negative Feedback removal."
If you'd like to do the above I'll remove the negative feedback.