Anyone remember USL vs. BSDi, or Sun Microsystems vs. Microsoft?
Although not exactly the same, this is somewhat of a similar argument to that old 1992 case. Based on some of the comments, I think the SC justices are aware of that case and the precedent that it set. This is a very complex case with very deep legal questions. Things that only a lawyer can love. IANAL, but I remember something about a Java case between Microsoft and Sun Microsystems where Microsoft was ordered to pay something like USD $1.5 billion to Sun for extending Java along the lines of their embrace, extend, extinguish mantra. I also remember Windows XP Service Pack 1.0a which removed Microsoft's implementation of Java from Windows.
The USL vs. BSDi (which later included UC Berkeley) was an interesting case about reimplementing code. The details of the settlement was sealed until the SCO vs. IBM zombie case (which is still kicking from my understanding). The case revolved around the copying of 6 files from Unix that was incorporated into the BSDi version of Unix, and the removal of copyright notices, and lack of acknowledgements in source code and documentation. A settlement was reached and everyone was happy, until now.
I know of one clean-room implementation of software that exactly fits this case: MS-DOS vs. DR-DOS. Bill Gate's Microsoft tried EVERYTHING to kill DR-DOS, but couldn't. Kind of a moot point now though, but the people at Digital Research went through MS-DOS and wrote a complete specification of it, including the APIs and then sent that specification to a group of programmers who reimplemented it. Since it wasn't the same, Microsoft couldn't call copyright protections on it, even though it did the same thing.
And there was Chamberlain Group Inc vs Skylink Technologies Inc. relating to interoperability of garage door openers. Granted, that one is kind of a stretch.