Sorry we are not sure how it happened. We could not duplicate this issue. Could you please help to provide more info on how to duplicate the problem? Ideally, could you please try a test folder and use some test files so that we can duplicate the problem in our test lab?
You can also make the synchronization a one-way synchronization from local to server.
If you don't want your colleagues to overwrite your files, you can help them setup a synchronization to a folder you share to them. When you share the folder, set the permission to read-only (i.e. View Original).