If the 1K in question provided you with a cr-1 by CALLING the 1K line, that is not doing it electronically/on-line and DOES require the 1K to personally visit the airport and sign an authorization form. If that's the case, UA was totally correct in denying you.

If the 1K'er requested the upgrade via their online account, then they were incorrect but my guess is the former situation, particularly as you used the "1K line" terminology in your post.