How to reproduce:
1. Open the attached project
2. Open 1.unity scene
3. Select cube
4. Open animation view and move to 0:30 position (ensure recording on)
5. In the inspector of cube, under the Test script, set angles to <0,0,-30> and click the "Set" button
6. You can see a new keyframe created of <0,0,-30>, but if you drag in the AnimiationWindow, the keyframe will snap to be <0,0,330>;

Not reproducible: 5.4.0f2

FIX: new API call Set and Get Inspector Rotation allow user to set and get rotation as how it is displayed in Transform Inspector Windows. aka: euler representation is kept.