First of all it isn't stated anywhere in the essay that the common goal of both being smart and wise is to be able to act in unknown situations. Were we talking about known situations, the ability to act would really be only about how much experience one has gathered and how much knowledge one was able to extract from the experience. By extracting knowledge from experience I simply mean learning how to act the next time the same situation occurs.
Both wise and smart people have to extract knowledge from their experience, but in my opinion the difference is how they use the knowledge.
Wisdom
I see wisdom as the ability to appropriately apply the knowledge to the unknown situation. To see what's common and what's different between the current situation and what one has experienced in the past. Acting is then based on heuristics of how to adapt the behavior which worked in the past to this new situation.
Intelligence
Whereas intelligence is according to me more about the ability to generate possibilities how to act, to predict what effect the actions will have, and efficiently search though the alternatives, which includes evaluating only the relevant ones and expanding them further while disregarding the irrelevant ones.
Of course what I described here were just simplifications, because no two situations are identical, so everybody has to be wise to some degree and also wise people usually consider more alternatives. But I hope you get my point.
I am curious to see what you think about both the essay and my reply to it.