So imagine you see someone suffering from an deadly allergic reaction and in your pocket you have an epipen or whatever can help them. You have no concern for money and let’s say you just have an infinite supply of epipens. You’re not in a rush and you don’t know this person therefore have had no opportunity to develop any sort of real dislike for them. You are one of the people most capable of helping this person, maybe the only person around like that. There is no reason for you to think you might fail in helping this person, in fact you are very confident in your ability to register an epipen and you get angry when people don’t acknowledge your skills. There is no occasion for the bystander effect to come into play and really, no reason why you shouldn’t help them, unless you’re a psychopath.
Do you help the person suffering from the reaction? Apparently no, according to some people here. It’s none of your business, you’re just passing by, you have no obligation, so it’s completely fine if you don’t.