Well, he did respond to you. So he could have responded to the GM also. And if he where present there, it's hard to prove he was a bot.

Secondly, SE are known for being slow to ban bots/RMT. In FFXI you had RMT botting 24/7 in sky for a year before they got banned. It's like they don't care that much on the current effect on players, only making big ban waves that they then can post news about.