Just as Apple lost when they tried to sue Microsoft.
Exactly. Going on the original post, there was legally no piracy on the part of anyone. However, the trophy for least innovation in the field of graphical user interfaces definitely goes to Microsoft. In other words, they wanted to copy, not improve and innovate based on another's idea.
To me, the clear evidence is that they started off with an inferior implementation of the idea of their predecessor (Apple) that took over a decade and four full versions to approach what they were trying to copy. Apple and Xerox both vastly improved upon the knowledge gained from their predecessors and developed innovative products that were unmatched by anything previous.