Choking isn't just losing though. It's losing, when you should win or are in a fantastic position to win, in a fashion that exemplifies your mental fragility playing a part in the loss.
SA weren't under any pressure chasing 434 until perhaps they got within 60-70 runs. Still a fantastic chase. Gibbs WAFG.
But that's a different ball game to chasing 221 in a World Cup knockout match against an unfancied team.