How do you tell if food is poisoned?

This was a rather silly question, so I interpreted it to give a bit of a tongue-in-cheek answer.  I offered the user some resources on good hygiene and reccomendations for avoiding food poisoning and accidental poisonings.  From the way the question was asked, I'm tempted to say this person was either having a good laugh or suffering from some sort of paranoia, there are so many non-verbal clues you miss out on in text-only interaction, but there's no reason to exacerbate that with name-calling.

Here is the link to the question:
How do you tell if food is poisoned?