I was the one who wrote that site, actually. Please keep in mind that I was focussing on that topic intensely for a few years solid, and I did careful research on all aspects of what I covered. I've known that alternate history has lots of butterflies; I tried my very best not to ignore them, and I was conservative in how I used the butterflies.
Wow, yofie, looking back at that post I've realized that I was very unnecessarily nasty there, especially the part about you not getting butterflies. I'm sorry.