Public Folder Recovery when Deleted Item Retention does not work in Outlook

I ran into a problem today where Outlook gave me an error when attempting to recovery a public folder from deleted item retention that was deleted by a user.  The error was…

Outlook was unable to recover some or all of the items in this folder. Make sure you have the required permissions to recover items in this folder and try again. If the problem persists contact your administrator.

It turns out that you can get around this error by recovering the folder via webmail.  Just use the following URL to show items in deleted item retention and restore from there…

http://<servername>/public/<path to parent folder>/?cmd=showdeleted&btnClose=1