I think I kind of get this.
The hospital staff start to suspect possible Amonita mushroom poisoning, given the symptoms. They need to rule out that possibility if they can, or treat preventatively if they can't.
Erin P takes the remains of the food to the hospital lab / toxicology for testing.
Questions start to be asked of the family about mushrooms either before or while the testing takes place. Do you as a family, or does anyone in the family, regularly pick wild mushrooms, forage for funghi, prepare mushrooms at home?
The family members start to talk about Erin's fancy dehydrator and what she uses it for.
Erin disposes of the dehydrator as far away as she can, as quickly as she can.
Erin calls it 'panic', and tells Asian grocery story.