Oops HBO, using real user data in your software integration tests?

I got two. Was wondering first if it was suspicious or an oops.

So HBO has some integration tests that make sure their system can send email properly. The way it does this is by sending some test emails to a test email list.

Except somehow, someone made a mistake today and the test email got sent to the real email list of all the subscribers.

I think that email was them flipping the switch and forgetting to remove the test email. This is my hypothesis as a seasoned Server Engineer.