Can anyone help me with this?

I went to the arena and I had a match with a player, (IGN Naught). He was a ranger and I was an assassin so I thought I had to make sure I get the first hit. And I did, I used Apply Poison I and Apply Deadly Poison I and used a Greater Courage Scroll. He didn't move at first so I took the chance and took him out quick. After that, he revived, and was suddenly moving VERY VERY slow (he was actually sliding most of the time), and sometimes even leaving the boundaries of the arena. Even if I get close to him to attack, he teleports away. Only my Ambush VI and Shadowfall I works, and while he's stunned I can use some attacks. I thought he was bugged or disconnected, but after a few minutes he fought back and it really irritated me. I wasn't able to take screenshots. I just wanna know if he's a hacker of some sort or there's a bug in the arena.

Any ideas what happened?

 

ranger has retreating slash and the other one is remove shock chain skill that leaps backwards.. if he moves very very slow ye able to attack u. he might used the sniper stance.. im not much familiar to arenas coz i dont enter the said instance. that is just my opinion.

 

Ah yes maybe it was Sniper Stance.. But I still wonder how come he can't be attacked.. Anyway, thanks for answering.

 

Sounds like a severe lag spike on his end, I have had players port out on me, then reappear 30 seconds later no one knowing what the hell just happened.