AI is frequently used to discover things that would take laborious amounts of time for humans to do.  For example, AI can be used to find the optimal configuration for a mother-board layout, or identify best fit parameters for a financial model.  Frequently, the AI can do a better job at a task and do it more qucikly than a human.  Therefore, in many applications, the AI is already more intelligent than the creator at specific tasks.  

Here are just a few things that AI can already do better than humans:

 - Playing Chess
 - Playing Jeopardy 
 - Detecting Cancer

To argue against the possibility of a super-intelligent AI is somewhat of a moot point since it has already been proven.