"What worries me is he's been reluctant to try one himself."

That should tell you something. At the very least it shows he is not an expert mycologist. There are only a few fungal species that I will eat from the wild, for example oyster mushrooms and morels. Even then I only eat ones I collect myself, since then I know where and how they were growing. To my untrained eye all I see here are fleshy gill fungi that could easily be mistaken for something toxic and potentially deadly.