Thanks for the mention. Unfortunately, the right answer in this case is undo. The last 48 hours view helps you fix tasks that you have mangled, but if yóu have actually deleted the task then it's not in your task list at all, so it won't show up in the last 48 hours view or any other view.
You can bring of a backup, copy the task from the backup and paste it into your task list. But only if you are actually taking backups and if you can recognize the desired task when you see it, which sounds unlikely this time.
-Dwight