@Wakko
Usually you can have a secondary party member (not the thief) converse with the victim, allowing you to get as far away as desired, usually about 30m and sneaking is decent, just depends on how far away the victim can see (break your sneak in their random pathing search)
They will usually settle for other player characters in the area when they come up empty-handed with the thief, as long as their inventory is clear of stolen goods, the victim will usually warn that player to be on the look-out and proceed to searching again, after about 30 sec max (for me usually) they will settle down and resume regular behavior until stolen from again by another toon.
_ _ _ _ _
On a completely seperate note, you are not forced to use Thieving but its definately a way to go, it helps with traps AND unlocking doors as well as pickpocketing so having a Lucky Charm player and a Thief always is a good idea for general gameplay, for the first act 1 point in Persuasion is enough for general checks but for convincing a guard your not where your not supposed to be? thats a bit more difficult so you can diversify in the first act and respec in acts after
_ _ _ _ _
My friend and i have done extensive testing with it and Lucky Charm is far more exploitable than the limited Thieving Skill, for instance, you find 2 Ornate Chests in a dungeon vault with a few vases nearby (all unlooted) you respec your Civil Skills to 0, and progressively open chest, open chest, reload, add one Lucky Charm, open chest, open chest, reload, add one more Lucky Charm (total of two instead of previous one), open chest, etc
Not like any loot found from that method? reload to empty Lucky Charm character save, open a vase, save game, repeat the above methods and new loot will be in chests
my friend and i did this exact situation and rather than getting one legendary belt, pants, or ring + one epic weapon, shield, belt, or ring + one rare something / we got one legendary shield with 2 resistances and +4 constitution, one legendary ring with several skill buffs and +3 wit, and rare pants with one resistance and +2 initiative
conclusion LC is far more exploitable and broken, but it allows you the ultimate freedom in becoming either an awesome 5 star godwoken, or re-rolling to intentionally hobble yourself to make the game harder