According to the BPMN specification, the Terminate End Event is supposed to terminate a process instance at the level at which it is raised, including any ongoing activity for sub-processes. But is should not terminate any higher level (parent) process.
With OBPM 11g it works differently (at least up to PS6), as raising a Terminate End Event will actually terminate the composite's instance. Except for human tasks, because as clearly stated in the documentation: "Human tasks are independent from BPMN processes. If you terminate a BPMN process while it runs a user task, the associated human tasks keeps running independently". The reason is that the human workflow engine runs separately from the BPM engine.
In the process below this will result in the situation that the Review Data task will still show in Workspace, while the associated process instance is already terminated. That was not the original intention of this model.
Conclusion: before considering using the Terminate End Event be well aware of its behavior. Consider alternate types of modeling, like raising a business exception that is caught by the parent process, which then uses an Update Task activity to withdraw all human tasks before actually ending. In this way you can prevent any human doing accidentally doing work for nothing.
Such a model would look like this: