Temple of Kopec bug

While in a party with my friend, we fought the boss and were about to talk to Alva. Well I decided to talk to her right away and my friend wasn't in the middle where it turns into an elevator. It lifted off and i laughed and said see ya have fun down there. Then he took a portal and was in the Ziggurat encampment with no gateway. He had to run through the whole temple again because of my shenanigans