Why can't I say anything right on the internet, anyway????

This girl posted some awesome doujinshi she drew, and said she had been selling it before at Sakura Con. I commented saying I liked it, but that I was dissappointed that I couldn't make it to Sakura Con to buy it.
Well, I apparently I said something wrong, cause she got kinda pissed at me in her reply. I tried to apologize in my response, but she ended up getting even MORE angry at me.... And I still can't figure out what I said wrong ;______;