About midway through he’s hanging in the middle of the walkway, knocking parts pff/down. He can’t be blocking out “what could happen”, he’s got to be quite aware of it (and think it can’t happen to him).
Of course, this doesn’t reflect the hazard at the location.
Generally these stacks emit Carbon Monoxide and heated air, which is why they are so high. To get it away from people on the ground. Even if shut down, their still is likely emissions from the solid chemistry going on down below.