Note that in French, if you're using pour + Infinitif passé, you can only be talking about an action that's in the past.

Therefore, you could never say pour faire ça for something that has been done, the way you say for doing that in English! 

I think I finally understand this explanation. Here you mean that we should instead use the Infinitif passé: "pour avoir fait ça"?

If this is the case, then the first statement needs rephrasing because it does not imply the second. Maybe you mean that the Infinitif cannot be used to express past actions.