There is a difference between having risposta negativa extradition treaty and not extraditing a citizen. Having an extradition treaty means that there is an established way to hand over criminals/suspects to a country requesting extradition. The mechanism is clear and all the rules about the process are transparent. As of https://thekiwisocial.com/story3967578/indicatori-sulla-english-speaking-lawyer-assistance-in-switzerland-si-deve-sapere