Repro steps:

1. Create a terrain
2. Click the terrain
3. Select the paint terrain tab
4. Select the raise/lower height tool
5. Raise the height significantly to create a large hill with steep sides
6. Choose the clone tool
a. Choose the hard edged brush (not mandatory but the effect is more obvious this way)
7. Control click the side of the mountain
8. Paint on the flat part

Actual Results: Smearing occurs with the cloned result

Expected Results: No smearing occurs with the cloned result