It has happened on occasion, due to the high amount of 10K moderators on SO that questions are migrated to the wrong site, and needs to be reversed. Although currently it is possible to re-open the question on the original site and delete the one on the destination site, it still leave the migrated too banner behind.
It would be useful if diamond moderators could reverse a migration, removing it from the destination site completely and re-activating it on the original site and at the same time removing the banners.
Previously it has been discussed educating the users around when to move questions, however this doesn't stop the problem.
As per Shog9
I have to admit I do like Shog9's suggestion regarding the post being closed as not programming related rather then re-opened, however, reasons for closing it on other sites should also be kept in mind, as this also applies to stuff being sent back forth between the sites.