They don't need "credible, academic validation in the public domain", they need a working product.
You hit the nail on the head. I can make an argument that this is a scam without knowing anything about physics.
If they truly had invented a free-energy machine, they would have patented it and then published the theoretical work and a description of the machine's construction. A number of scientists around the world would then undertake to duplicate their findings and validate them.
Any other course of action points to a scam. It's very likely these people are simply trying to create a media buzz which they hope will translate into funding.
Apparently they don't believe in it enough to invest any time and money into developing a product.