Some CARO terms don't have labels

[hlapp]

For example, http://purl.obolibrary.org/obo/CARO_0020004:

$ curl -X GET "https://kb.phenoscape.org/api/term/labels?iris=%5B%22http%3A%2F%2Fpurl.obolibrary.org%2Fobo%2FCARO_0020004%22%5D" -H "accept: application/json"

{"results":[{"@id":"http://purl.obolibrary.org/obo/CARO_0020004","label":null}]}

Is this expected? Note that there are CARO terms that do have labels in the database, so this is at the least quite inconsistent. (It's also throwing off some tests in Rphenoscape that by random sampling occasionally hit a CARO term that doesn't have a label.)