That's ok, we disagree. But I think you're looking at what
did happen, as opposed to what she
expected to happen.
If the plan had gone as she foresaw, the dehydrator, the clinical staff, public health authorities, commercial store selling mushrooms etc. were all irrelevant.
The guests were meant to all die, relatively quickly, at home, without any of the above actually happening. She would be the sole survivor of the lunch and thus the only one who could say what occurred. The police knock on her door, she lets them find a container with DC residue that one of the guests brought to the lunch. Police then move along to establish a tragic accident, caused by one of the guests. When this
didn't happen, of course she was presented with a




sandwich and the whole thing looked poorly thought out.
She should have pulled out when Simon didn't come. That was her big mistake, with the months of planning and money already spent, overriding common sense to bide her time IMO.