Maybe a bot?

I was levelling my warrior around with my paladin friend in Zul'Drak yesterday. It was as usual, be it quiet or ganky. However, we discovered an oddity in the crashed necropolis of Kolramas. We were hunting some Skimmers scourge nerubian when we ran into a Rogue by the name Noerg (iirc). I didn't take screenshot or anything, but this particular Undead Rogue run at our group, right into the crowd of mobs in front of me. At first, I thought he was just helping me finishing off the mobs before I realized he was targetting me. The most peculiar of all, he was using an auto attack and right in front of my warrior who was at the moment using her Protection spec. Of course, as I activated Shield Block and Revenge, complete with the Holy paladin DPSing and healing on my side, this Undead Rogue got swept along with the crowd. At first we were just going 'wtf' at the poor attempt of attack this rogue pulled.

The Rogue ressurected and started running around for Skimmers as well, on foot, without stealth on. My friend decided to follow him closely, and got no reaction from the rogue. The paladin also noted that the rogue only had one weapon in hand. Now I never met a bot before, but I started to have my suspicion. Since I don't know WoW bot behavior and had no screenshot, I was discouraged to send ticket to the GM. My friend tried to auto attack the rogue, until suddenly the rogue vanished. But not attempting to strike back.

I want to know if this is a sign of botting or not, so that if I caught players with similar behavior and pattern, maybe I can make a proper report in the future.