To expand on this, it's good in general to return leaked code of active-development projects because that helps the social contract of turning work into something that can be sold. So if I found jakebasile's 2015 code in an alley, it would be in some sense good for everyone for me to return it.
But that doesn't apply to a 20 year old master for starcraft. There is no promotion of the useful arts in returning the CD in this specific case, and it's a hugely relevant cultural artifact.