When a complete event is changed to incomplete and the event diagnosis is Undetermined, that event diagnosis can stay if it was manually set by a user, otherwise if it was automatically set by the application then it must be deleted and replaced by a Pending event diagnosis.
When a complete event is changed to incomplete and the event diagnosis is Undetermined, that event diagnosis can stay if it was manually set by a user, otherwise if it was automatically set by the application then it must be deleted and replaced by a Pending event diagnosis.