Ballsy to not use a sub to bring on fresh legs at some point in the extra half an hour of play, just to have one available to switch keepers for a shootout if it happens.
Or, it might actually not just be ballsy, but also kinda dumb. If you brought on a fresh striker or mid you may well have won it without needing a penalty shootout.
He put on Huntelaar to do exactly that.
I went back and had a look, and yeah, they didn't have any more strikers on the bench after Huntelaar. However they did have a couple of midfielders, De Guzman and Clasie, who could have come on for, say Wijnaldum, who was looking cooked by the end. Fair enough leaving on the experience of Van Persie, Robben, Sneijder and Kuyt though.
Edit: So I guess not so much dumb as very unusual and risky to not use all your subs on outfield players in 120 minutes of knockout football in hot and humid conditions.