I'm not saying that you can distribute the code or compiled code outside of GitHub. As I understand it (IANAL), it seems like you have the right to edit this repository on GitHub as long as it stays on GitHub and not redistribute it through any other avenues.

Edit: Someone mentioned that Justin uploaded this repository, and not NaturalMotion. If Justin doesn't already have the right to distribute this on GitHub, then the rights granted to you by the ToS probably don't apply.