Indeed, the author opens with that same observation:

Now, I’ll be the first to say that sometimes Atheists are insulting towards Christians. In fact, there was this one time when myself and another atheist was arguing against this Christian, and the atheist said something so cruel, so outrageous, so outlandish, so personally insulting and cruel, that I publicly backpedaled and had to distance myself from that comment. It was the most offensive way she could have insulted the Christian. Now, as someone who has been through thousands of internet debates in his ten years of religious debates on the Internet, I’ve heard a lot of insults. I’ve been called just about every name in the book, and I’ve heard the side I’m arguing against get called just about every name in the book. And yet, in the middle of ALL THAT, THIS insult really took the cake. It was terrible. Horrific.