Earlier quoted context omitted.
I am well aware of the joke that is the clean-room process. Note that it supposes that the first team has access to the specification, source code, or any IP-encumbered indication about how the software in question works. In the case of Skype, the only public information we have is the binary.
Note that it supposes that the first team has access to the specification, source code, or any IP-encumbered indication about how the software in question works No it doesn't. The Wikipeda link[1] mentions the original IBM PC clean room implementation by Columbia Data Products. It doesn't have the complete story of that, but from memory the way it worked was CDP had one team documenting how the BIOS responded to inpu…
From the ruling: "Some works are closer to the core of intended copyright protection than others. Sony's BIOS lay at a distance from the core because it contains unprotected aspects that cannot be examined without copying. The court of appeal therefore accorded it a lower degree of protection than more traditional literary works."
Thus one could try to make the same case for Skype.