If you're referring to the 2012 case of EA vs Zynga, it doesn't look to me like it established different jurisprudence. The artwork in that screenshot comparison looks very obviously copied. For copyright, copying something doesn't mean that you have to copy it verbatim without modification, as derivative works where you take the original and modify it slightly can still infringe upon the copyright holder's rights.
This is why projects like Freedoom or Hedgewars recreate all game assets to make them look quite different. Just making minor changes that make it obvious that the original artwork was used as a guideline is not enough of a defense against an accusation of infringement.
What is a defense, however, is when copyright infringement is not willful. If you and I happen to make the same artwork but we can prove that neither of us looked at each other's work and the similarity is just a coincidence, then it's unlikely that we can claim copyright infringement.
This is why projects like Freedoom or Hedgewars recreate all game assets to make them look quite different. Just making minor changes that make it obvious that the original artwork was used as a guideline is not enough of a defense against an accusation of infringement.
What is a defense, however, is when copyright infringement is not willful. If you and I happen to make the same artwork but we can prove that neither of us looked at each other's work and the similarity is just a coincidence, then it's unlikely that we can claim copyright infringement.