The issue occurs in the case where the document id is not the same property as the entity id:

@Entity
@Indexed
public class Insurance {

	@Id
	private String id;

	@DocumentId
	private String docId;

	...
}

HSearch then makes use of the Criteria API which we do not support yet.

If it's deemed important, I guess we could "fake" it as the required criterion is very simple (just a simple property comparison).