It did sound like he slipped at one point. I would have loved for him to go to the summit, but it’s quite a climb!
He was probably slipping on some tefra here and there, or just slipping on the lava because it’s so uneven.
It’s got to be awfully tempting out walk out there but I’d be spooked too. He should have gone around to the backside and followed the footprints Charles’ friend followed when he went out to Big Daddy a while back. He wouldn’t have had to worry about voids then. And he could have climbed up the slope too. That WOULD be cool!
I bet he goes out there again and goes farther next time. The desire’s strong in him. LOL