They (encounter guards) don't care what you're doing 1 hex next to them, they will always open fire as long you are doing that for more than N seconds. That's why the "Keep your distance" yelling. N is just a bit too low recently (fixed on next update), but stealing itself works as before (one of "befores", anyway), except with increasing xp (due to increased difficulty) for consecutive steals from the same critter.