Barbarians capturing cities

I've seen barbarians attacking a weak german city but not capturing it (I captured it first), is it possible for them to occupy a city and winning 'he threw a car at my head'?

Barbarians cannot occupy or capture cities; they can only attack and pillage golds from them. "he threw a car at my head" will be earned when the defense of the specific city reaches zero.

I used "World Builder SDK" to place 7 barbarian pikemen around my ancient era city (create scenario), and I got the achievement within 10-15 turns.

To get that achievement you need to purposely create a bad situation and let it happen, like raging barbs in a geographic area no competitors (AI or CS) are attracting/killing off barbarians.

Deity raging barbs...it won't take that long