I click 'exit case' and it doesn't grade the case!

You will need to complete all of the questions prior to getting your report (unless you have checked practice mode). When you hit "exit case" this will save your work and is for convenience if you are not able to finish the case right away. Clicking "exit case" will not end the case. It means you are prematurely leaving the case, but in the online/web version, it will save your work, so you can return and start off from where you started.