[dvfjsdhgfv]

Elastic may present it this way, but it doesn't need to be. Personally I decompiled different binaries numerous times in order to understand how an implementation works, but it never occurred to me I could "copy" the code somehow - the decompiled version was usually a big mess, so I had to figure out what is essential and reimplement it myself. In may jurisdictions this is perfectly legal. The jurisdictions of the USA and EU explicitly allow decompilation for the sake of interoperability.