he is level 34 in the demo. if you watch the bandits carefully the second one jumps and looks around, but he is well hidden and the shadows and is quick with another killing blow.
Level 34 should take a hell of a long time to get to, then.
And I sure as hell wouldn't go running into the shadows out of which an arrow just flew and struck my companion, that's for sure.
The arrow obviously came from behind them, and he was only looking around in front of him.
Any normal person's reaction, bandit or not, would at least be to whip around and then try to hide.