Why are little dried mushrooms so DANGEROUS?

Factual Questions
1

I bought a package of dried Chanterelle mushrooms, and the instructions on the back said you should wash them and then reconstitute them in water before eating. It also has in boldface, “Warning: DO NOT EAT DRIED MUSHROOMS!”

Not that I would, it might be too much like mushroom jerky, but why exactly are these dried chanterelles so deadly? Fungi-based disease? Make your eyes water?

Someone save me from my ignants

2

Dried mushrooms suck up quite a lot of liquid as they rehydrate, and at low temperatures, eg 37°C, the rehydration can take a while.
I expect you could eat enough of the things to cause intestinal upset as they suck the juices out of your bowels.

3

So, as they expand, they could block & even rupture one’s intestines?

I knew I didn’t trust those things.