Since you stated that your friend's ticket priced out at over $1300, it sounds like he/she may have purchased a full-fare coach ticket. If the fare was coded as a 'Y-UP', regardless of elite level they can be placed into F at time of purchase. So, if they bought their high-fare ticket 14-days out and your EUA was processed 6-days out as a Plat, they conceivably could have been upgraded before you and, if F was full prior, be waiving to you in the back at the time of departure.

As to whether it's fair to higher-level elites, NWA has determined with their full-fare vs. discounted UG policy that they favor full-fare pax over higher-level elites. Just business, nothing personal against Plats, and an obvious carrot to buy Y-fares on busy routes.