Unrecognized relay in exit address '[scrubbed].exit'. Refusing.

This line appeared in my tor log the other day.

Unrecognized relay in exit address '[scrubbed].exit'. Refusing.

I don't know what it means, and a quick search didn't return anything useful. I wasn't doing anything out of the ordinary; just using Tor Browser. I use the system-installed Tor, so it could have come from anything on the system I guess. Safe logging was enabled, so I don't know what address was requested.

When I tried to reproduce it by making an explicit request to foo.nonexistant.exit, I got this.

The ".exit" notation is disabled in Tor due to security risks. Set AllowDotExit in your torrc to enable it (at your own risk).

What does the first line mean, and why wasn't the request rejected by AllowDotExit=0? Is this something I should be worried about? Even if it's benign, hopefully users who get this warning will find this ticket in searches, since I've been unable to find the exact message anywhere.