Routing rules are never just black and white - there are all sorts of exemptions, exceptions, adjustments, and bent rules for various reasons. Can you supply your actual route you're interested in? A lack of backtracking is not enough.

Also, as has been stressed in this forum for years: nobody here knows anything for certain, we only know what we've managed to do in the past. If you want to know the actual rule, call Aeroplan and ask. Then call again and ask again, in case your first agent was wrong.