At what part of this issue scam happened? Even if they are alt account, They both finish post quota that equivalent to work done. There’s nothing lose here because all payment done was matched by required post.
The scam occurs due to the greed of people who join many accounts in the same campaign. Campaign managers create rules for each campaign they publish. It is not without reason that campaign managers only allow one account per user to join. You cannot see such cases with the amount of work completed. This violates campaign rules, clearly cheating the manager, as well as other participants who also apply for the campaign.