Actually, kits do pass now and then, no matter what you do. It does happen, it is inherently a part of life, and it's not that rare with rabbits. I had streaks of good luck for years, but thinking you just need to do whatever someone on the Internet says will save all kits is just wrong. Does even do sometimes single out kits when they think something's not right, or kill whole litters for whatever reason, does happen.
Decisions need to be made , advice has been ignored, errors occur. I can see that it can be not obvious in time that something is going wrong when you try to handraise a kit the first time, watching the little one suckling away gives false hope. Raising rabbits has a steep learning curve. And there is no way to tell how it would have ended otherwise. Uttering such harsh words from a safe, comfy position is too easy.
Pardon me, but this whole topic is not about your, or my, feelings. Getting offended over something on the internet that doesn't go my way, well, not easy but one can work one that. I can't count the posts I deleted before pressing the send button.
Since you mention J., I'm still pretty much of the opinion that this was kinda a troll, the timeline simply just didn't add up in those dramatic episodes. I know such people in RL.
Anyway, there's still the rest of the litter to care for. And I rather have people ask questions than shying away from grumpy old men. Life goes on.