I didn't say anything. I feel like it would be churlish, like if someone knitted socks for you and you said, "Oh, you dropped some stitches." I mean, yes, technically, an error has occurred, but now I have HANDMADE SOCKS. How can I complain?

By the same token, people are just about never moved to make secondary fanwork of my stuff, so I don't feel like I can say anything but "Yay! Go look!" if it's of a minimal standard of quality.