I did a bit of searching, but I cannot seem to find anything related to this specifically. I did check to see if this was fixed in later versions, but nothing in the "Fixed" list for later versions mentioned it. Perhaps this is intended behavior? If you click on an animator component, then switch to the Animator window and double-click an animation (The inspector will show the loop time, loop pose, etc..), you cannot go back to the Animation window and access the animation list. Again, I don't know if this is intended, but once you have canceled out of the inspector that shows the various settings for looping, the animation list is once again accessible.