So what if the T4 was correct and turbotax missed something in the auto-fill. 

Let me tell you a little story. A few years ago I let autofill do it's thing and filed my taxes. Remember that Turbotax is simply using the information from CRA that they currently have but they may not have all of your T4 information. After a month or so I was informed by CRA that I owed another $800 or so and that was a bit of a shocker (as pensioners that may not sound like a lot to those still working but a major hit when on fixed income). Since that time I have NEVER allowed Turbotax to autofill my return. Again not Turbotax's fault but CRA clearly states that it is the taxpayer who must make sure that the information supplied on your return is correct. So in this case a word to the wise, you better double and triple check that the information on your filed return is absolutely accurate.