Okay, Devil's advocate, I get what you are trying to do, but your argument is a stretch at best. I think the intention is theThere is really no such thing as a "greater good". Is it worth it for one person to die today so another person can die tomorrow?
To reiterate: accidental vs. deliberate. The problem is the intention. She killed fish because she is devoid of emotional intelligence and therefore reacted badly. IF the dude accidentally killed any fish because of research negligence, I'm sure he wasn't happy about it, chanting "die, die, die" and posting videos of it. ACCIDENTLY hitting someone with your car because you didn't get your brakes checked and couldn't stop is VERY different from ramming someone with your vehicle on PURPOSE.To pose another question how many fish did that guy accidentally kill to end up with the ones he had? This is the reality of keeping any pet and fish are definitely the worst in this regard.