You have a post in forum X. You create a report about it. This report is now visible to the moderator of forum X. Now you move post to a forum Y.
Reports contain node data in a serialized form in the xf_report.content_info field. And this info is not updated on thread/post move/copy operations.
So, after we have moved our post, it is still visible to the moderator of forum X, and invisible to a moderator of forum Y.
What can be done about that? Of course, we can write a handler, that will update at least data in active reports on thread/post move/copy. But may be there is another solution?