Approval workflow problem

I want to have a state change which is triggered by an approval. easy enough to do.
However, I would like to have the possibility of changing the state manually not available since I cannot explicitly query who changed the state.

I added the workflow to the approval and that works, but when I remove the transition to that state in the workitem workflow, the approval also does not do the state change even though the action is still defined.

It appears that the transition must be defined for the state change which is being done by the approval.

Is there a way to make the approval the only way of triggering the state change?