Yes, I would agree NZ is generally very safe, to go on a Tinder date and be murdered is not the norm, but the comment about NZ having a dark side holds true IMHO. Violent crime has increased in recent years, probably on the back of the 'P' drug epidemic that has infiltrated the country. Prisons...
colinz may be better place to judge that, being based in Auckland? There is a strong gang presence in New Zealand and brutal murders are not uncommon. Just last week a pensioner in Wellington was decapitated.