You'd have to use a very strange definition of edible. For something to be edible it does not only need to be able to fit down your throat, it has to be capable of nourishing you without harming you. You can swallow paper and it won't harm you, but it also can't nourish you and is thus inedible. You can eat this mushroom and it'll probably provide some kind of nourishment, but then it will swiftly kill you and thus it is inedible.

I would accept a definition of edible which includes things you can't digest. For example, gold can also be a food additive referred to by the code E175. Can't digest it, but it doesn't hurt you. So I could accept someone referring to gold as edible. But I think the barest, most universal element of something being edible is that it doesn't kill you. If literal deadly poison is considered edible one must wonder what the word "edible" is even supposed to mean.