If he didn't explicitly take credit for the mod, but left it blank (as I understand it), then on the surface it screams MADE BY ME. However, since we don't know if that was the intention or not, it could very well be a FuBar situation and misunderstanding. All I'm saying is that apparently it doesn't have to be premeditated credit snatching (because then it would have said MADE BY ME). Now, to forget to credit someone for the work they did on a mod and then release it, probably ranks up there with the worlds biggest faux-pas and isn't to be excused, unless he actually appologized for what he did, then maybe...
Personally speaking, I know that I'm gonna need a powerful assortment of code to get the Minnow released and am already asking permission from everyone who has mods/code floating around that I might need. I'll probably goof up the credits list upon release (just because it's the one thing I don't want to goof up, QED), and I'll answer for it, appologize, repent, edit, and move on.
If the guy goofed, he should anty up for it, and make ammends. Best way/only way to get past it.
Acolyte does credit like this: "All credit for everything in here goes to other people (see long list), all credit for putting it in one mod probably goes to me. All credit for bashing on a keyboard for 6 months, definitely me. All credit for putting up with me, my girlfriend.., and you guys
"