Are you using the outlook.com app or a web browser to access your email? There are different things you can try for each...
If you're using the standalone app, have you looked for Fred in the "people" tab on the outlook.com main screen? Outlook.com draws its autocomplete list from a variety of sources. The most likely option (which it looks like you've already done, but I may have misunderstood) is to make sure Fred doesn't appear in your contacts list, and that his name is not associated with the manager@somewhere.com email address. If Fred is still in the "your contacts" list in the People section, then select his name, and click on "edit" on the contact record that comes up. You can then delete the record entirely, or at least put a non-existent email in for him, so that it won't associate Fred's name with the manager@ email address.
Otherwise, if you're using a browser-based email client to access outlook.com, the other obvious option is that it's pulling the information from a cookie; try clearing your cookies. If you don't want to lose all your other autcomplete information, depending on your browser you may be able to choose which sites to clear cookies from and only get rid of the outlook.com ones, so that important info (like the autocomplete for your TalkMorgan login details, for example) don't get binned at the same time.
