To be clear, I'm not denying that what you say is literally true, just that by the time I'm done filtering that particular fact through my personal belief network and personal experiences, I still end up saying that my story is more likely. It's true enough that they put a "NULL" in, it's just that the way the private firm does that is most likely that the field agents leave it blank, some software somewhere puts a NULL in some database, and the report that comes out for the enforcing authority has NULL in it. For a reporter, it's not a false statement, it's just not all the technical details.
With this story, the responsibility ends up distributed in a very plausible manner I've seen many times over; HN readers could fill in a dozens of similar stories no problem. It's a problem characteristic of these sorts of systems and the way they tend to communicate with each other.