Yeah I agree it was very natural; didn't have anything out of the blue. Although he could be cheating, his opening is really weird; although white didn't take over the advantage, I also find it kind of strange how weird black plays for 1500.
Might want to look @ more games first before deciding.
I was playing some atomic (of course) but noticed a 1501 making some questionably... good moves?
replay: https://www.chess.com/variants/atomic/game/65881540