Then I suspect it was either the politician, or his wife who was the intended target. But if that's the case, why poison all the dishes in the first place? It seems a bit excessive, and would draw undue attention, unless the aim was to make it look like severe food poisoning. Of course, poisoning all the dishes would guarantee that the intended target would receive the poisoned food, but then how did the perpetrator know which courses the target would be likely to order?

This is certainly a very intriguing case. I don't suppose the authorities on your world would mind a helping hand, would they?