How to reproduce:
1. Open attached Unity project "testbuganimator"
2. Load "test" scene
3. Enter Play mode
4. Note, that object is not changing it's position
5. Stop Play mode
6. Open Window --> Animator
7. Select "New Sprite" in the Hierarchy
8. Delete unused state "testanimation"
9. Enter Play mode
10. Note, that object falls because of gravity

Expected result: Deleting unused state makes no difference on object's behavior.
Actual result: Object's behavior is different after deleting unused state. Before deleting state, unused animation still influences object.

Reproducible with: 2017.3.0a2, 2017.2.0b5, 2017.1.0p2, 5.6.3f1, 5.5.4p2