Mecanim adds rotation to animation clip during animation apply

I am getting rotations in the shoulder of my character when I create the animation clip. I bring the clip file into unity (from Maya), scale the model, apply humanoid rig, the shoulders do have to be reassigned because they default to the wrong joint (I don't think that matters). I then create the clip time and the animation looks correct. But then as soon as I apply the animation clip edits mecanim adds a huge rotation at the last frame of the clip bringing both shoulders up in the Z axis. It's over a 90deg. change in a single frame. Here is the really weird part, when I open the FBX back up in Maya, those rotations are not there. Unity is just adding them for some reason. Also, this error follows the end point of the animation set in Unity. The animation is actually only 31 frames of movement, but if I put the end point at some point later in the clip, say at frame 40, then the shoulder rotation will occur at frame 40.

Thanks in advance!