Suspicious of botting

I don't know really where to post this, so if this post is not in the correct place - sorry.

I encountered a very suspicious person. At first I invited him to a group to do the same quest as I am on. He neither accepted for declined and proceeded to walk around and kill mobs. I tried inviting him again after the period of waiting for a response expired. Still the same outcome.

So I started asking him random questions and saying hello. No response whatsoever. Didn't even stop walking and killing mobs. I don't know if this guy was just anti-social with me, but I thought he was suspicious about it. I might be wrong though.

Here are some screenshots of the guy I took (they are in correct order and been taken inside a period of a few mins):
http://postimg.org/image/98odn4rxp/
http://postimg.org/image/jcd3ja8od/
http://postimg.org/image/frh80244t/
http://postimg.org/image/srsywhqp9/
http://postimg.org/image/6h53witf1/
http://postimg.org/image/9ci73dxf1/
http://postimg.org/image/whslpe2jx/
http://postimg.org/image/quw8rx019/
http://postimg.org/image/wx3vieoh9/