So is the right process to report the post? (I'm assuming reports go to the home instance's community moderator.)
And if that's the case, does that mean we need to avoid clicking the checkmark to "resolve" the report on our instance until the remote moderator has done something about the problem?
Do you have some time to test it? You can post something to Ninja Tea Room and then report it. Let me know and I'll confirm that the report exists on our site. Then you can resolve the report and I can confirm one way or the other whether the status changes locally here, and whether the reason propagates. We will take care not to ban you. :-)