a long time ago I had heard (second hand) about a family that liked to pick mushrooms and consume them. Apatrently they went out one day picked some. One of the daughters was not feeling herself and chose not to consume them.
Not long after eating the mushrooms everyone who consumed the mushrooms died. The girl who did not eat any survived. The moral is that most mushrums are poisonious, and Identifying them may not always be 100%.
Out of all the edible plants I know of and of those that are experts on edibles, eating mushrooms is considered an unwise choice.
Are there experts on mushroom eating that know all the forms of mushrooms and there variations, heck yeah,, I know I am not one of them.
I am sorry the man eneded up in the hospital, and I hope he recovers.