AFAIK Emad Mostaque is not (yet) an AI expert at all, he's a rich guy (former hedge fund manager) building a business that provides the funding for AI experts to do their thing. Stable diffusion itself was built by a team of academics [1], Emad is not a coauthor. Not to take away anything from what he's accomplished -- it's quite incredible -- but it doesn't mean he knows how to (learn to) build AI systems or do AI research himself.
[1] https://github.com/CompVis/stable-diffusion