I was playing against tliu. Being a friendly gentleman myself, I couldnt help noticing that his username suggested a surname of Liu, a Chinese name. I decided to type 你好 in the chat. He promptly was disconnected. I resigned the game as penance for crashing him.
Thanks for the report, Boogar!
I tried this just myself, and there was no problem of disconnection or crashing a client. I'll ask around among Chinese/Japanese players if they have encountered similar behavior as you described, maybe it happens only on special circumstances.