Judging by that video there were only about 5 people fined (from the confiscated apples at the fine paying counter). And one was on a Singapore Airlines flight as well. 5 people, 4 from one aircraft is not a lot. It shows that the rest of the passengers on those flights either ate their fruit onboard, paid attention to the inflight video and left the apple on the plane, realised they have fruit when they filled out their legal customs document declaring they had no fruit or saw the signs before customs and dumped their fruit in the numerous yellow contraband bins.

Why should there be discretion by the customs officers? The law states that a $200 fine will be given for anyone trying to bring in undeclared fruit to New Zealand. If the officers let some people get away with it because those people made a mistake and didn't realise then that makes a farce of the whole thing. If you are being fined $200 and see someone else being let off for the same thing I don't think you'd be particularly happy. An analogy is saying that a traffic cop shouldn't fine you for speeding but should fine car manufacturers because they make cars with inaccurate speedometers.

Furthermore, shall we contrast the politeness and customer service skills of NZ customs officers with their customs/immigration counterparts in the USA....I think we all know who would come out on top there.