Outlook Missing Appointments 2 - organizer was an invitee

In my earlier post I talked about the most important piece of information to remember when troubleshooting missing Calendar appointments:

Deleting a meeting invitation or update will delete the associated appointment.

Sometimes we see a special case of this: a meeting invitation was sent out, and now everyone seems to have the meeting in their Calendar except, perplexingly, the person who organized it.
This usually occurs when a meeting organizer invited a Distribution Group (DG) of which they are a member. Typically what happens is something like this:

• George is in the Sales department and wants to set up the weekly department meeting
• So he doesn't forget anyone, George invites the SalesDept DG in his address book
• Because George is a member of the SalesDept DG, he also receives an invite to the meeting
• George knows he already has the meeting in his calendar because he only created it a moment ago, so he deletes the invite from his Inbox
• Outlook removes the meeting from George's calendar

The 'solution' to this problem is for George to always remember to expand out any DG he invites to a meeting before sending. But George wants to know how he can fix this meeting where the mistake was already made.
If George is lucky enough to be running in an Exchange environment where Deleted Item Recovery (aka The Dumpster) is enabled, he should go to his Calendar, select Tools > Recover Deleted Items, search for the meeting by subject, then restore it to his Calendar. He can then Cancel the meeting and re-book it with the SalesDept DG 'expanded' so that all the invitees appear individually.
If Deleted Item Recovery isn't available (or all this happened a long time ago and was only just noticed, so the item has already been purged from the Dumpster), the only option for George is to ask his colleagues to each delete their copy of the meeting from the Calendar and to re-book it.
A variation on the symptoms I described is where the Organizer has the meeting in their Calendar, but they are no longer able to make changes to it; the options available are the ones they would have if they were an attendee, i.e. Accept, Decline, etc. This usually occurs as a result of the problem above, but where further attempts have been made to get the item back either by having it forwarded from an attendee, or by recovering the original invite from the Deleted Items Folder. The root cause and solution are, however, the same.