More likely they let it expire or the registrar messed up. (DHH claims the latter: http://twitter.com/d2h/status/1590279638)
(Speculation: Why don't US registrars usually offer autorenewal? Here in Europe, especially Germany, it is unthinkable that my domain would just expire. I get auto-renew by default, no matter how I pay. Conversely, with the US servers and domains we hold, sometimes people don't even get payment reminders before the expiration date. Only when it's too late do you get a notification. I find that strange.)