Yet he seems to remain remarkably composed throughout

Effectively soloing on ice that thin while it's in the process of melting? I'm no ice climber but I'd say this guy doesn't have long to live in statistical terms.

Adamson did die on the Ogre a year or two after this was filmed, but nevertheless thin ice can be surprisingly climbable, it's just obviously not protectable. If it's not that steep, it's not even particularly hard as you aren't swinging or kicking as much as on thicker ice. With thin ice it has generally formed at same time (i.e. over one cold day, so it doesn't have layers in it as later season ice does. That make judging it easier as it tends to be very consistent.

I didn't know that. But I just had a quick read. Apparently the first attempt saw him break his leg after a 30m fall then both of them fall another 100m when the belay ripped, it sounds like luck alone that they didn't die then and there. You can only be lucky for so long if you keep pushing it that close to the limit.

It's hard to tell how steep the route is in the video, or how far he actually is above his belayer (far enough to be seriously injured is almost certainly the answer though) but I was struck a little that he didn't opt to downclimb to the gear - that suggests it was a was a pretty hard and sketchy but of climbing.

And then there is the fact that you can see water running down the ice and dripping off it... again, I have very little knowledge here but that just intuitively seems like a serious warning sign on such a thin, poorly protected route.