Steps to repro:

1. Open Unity;
2. Create new project;
3. Turn on Collab Support in Services tab;
4. Save scene and project;
5. Click Collab button;
6. Click 'Publish now!' button;

7. Notice that Collab windows has closed;
8. Quickly click Collab button again;
9. Click Cancel;
10. Observe Collab button state.

Expected result:
Either operation is reverted (you can still push current change) or change is pushed (green Collab checkmark button is displayed). See attached expected.png screenshot.

Actual result:
Collab shows incoming changes, which is basically currently made local change. Collab button is orange (it proposes to update to latest commit). See attached actual.png screenshot.

See attached video.

Notes:
- Reproducible in 5.6.0b5, 5.5.0p1;
- Reproducible on Windows 10 and OSX 10.12.2;
- Happening only when cancelling uploading during its final stage (100%) or on very small commits.