I take GoT spoilers very seriously. It had to be a bannable rule in my old Teamspeak. Because I've warned him about this before personally, but its only his second ban, this will be a 24 hour ban.
Your other ban is for chat abuse as well, so expect repeated offenses of the same nature to shoot up in ban time even more.
edit: don't open the spoiler if you haven't read the books noobs
