Since you cant seem to grasp what Stoutertaru is saying let me lay it out for you. You join as a tank with 2 dps and no healer in another party there are just 2 dps waiting for a tank and a healer not in progress. You friend marks in progress roulette and joins the 2 dps<They still don't have a tank so no duty pops>. Which means the group of 2 dps were waiting for a healer before the group of in progress. The DF doesn't prioritize in progress > newly formed. Just because your friend didn't have a duty pop doesn't mean that they didn't join a party waiting for an instance.