I just think it would be hard to show that you came up with a work independently and had never seen the other work if your work was identical to someone else's, that's all. I'm not saying you couldn't, just that it would be rather hard to get them to believe you.

Then again, the judge simply took the plaintiff at his word when he was shown a bunch of other similar works and he claimed never to have seen them. So maybe you could convince someone? The same option was, apparently, not available for the defendant because their products were sold side-by-side and the plaintiff used the image first.