Copyright - Source code that has been copied. Patent - Monopoly on an idea. Trade Secret Law - N/A. They are former employees. Non Compete Agreement - Agreements in restraint of competititon are void in California.
Shred's story sounds credible to me. The fact that Smule offered to make this lawsuit go away in exchange for equity sounds a lot like extortion to me. Why would they settle for a % of a company when they already own 100% of the secret sauce that was stolen? If their claim is as baseless as this article [1] suggests, RICO or anti-SLAPP laws should definitely apply.