Didn’t know they actually published some source code. I looked at their GitHub account, unfortunately almost all of their repositories have this in their readme:

This is proprietary software owned by Anego Studios. All rights reserved.

You may NOT sell this software in any way, shape or form. You may NOT distribute this software in its unmodified form.

Which part of it is open source?

It’s not about “someone else probably will”, it’s about “someone else already has”. No one is advocating for diffusion of responsibility.