Hi Anjarikam,
one option, you could apply, that you turn the UI to read-only mode after saving and do unlock. After that you can explicitly start your workflow.
Worflows can be started internally such way also Workflow Initiation, but this require touching the BO.
Actually, no one can ensure you that the workflow engine starts processing immediately, so this problem can happen not only in the case above, but the probability is much less. So if you turn to display mode after save, you'll most probably succseed. Anmyway, there is no reason to keep the incident document ready for input, after it has been assigned to someone else.
Regrards
Attila