Town hall > lv10, gold/mana vault < lv 16. Hero evolved twice @@.
[edited by Cichociemiak]
Indeed, he used gems to skip lack of gold. Pay attention if you have not enough of gold, you can buy it with gems. Therefore it is not bug. Next time don't write name of someone cause right now you found P2P player.
Telling that i'm moving it to ~Off-Topic