This just happened to me. I have my DC running while I'm at work and I literally just stepped away from my desk for like 30 seconds and my raid was already completed.
I get it. Y'all want the rewards. I'm just surprised this is the first time this has happened to me since the beginning of Ragna Break. At least I didn't lose raid stamina.
I remember someone saying earlier during the Liberated Maat banner that they pulled her from the chips event reward 5-star Dark Ticket.
I hope someone has information on this. It is the deciding factor on whether I use the blood gem summon or grab a ticket lol