Ned...
How could someone not realise the error in the second photo and know that instead of the steel shackle taking all the weight, that the weight would be taken by a rubber o-ring.
Read the report...it is very revealing....I have seen it happen, not necessarily with harnesses, but certainly watching someone preflight an aircraft.
Some more excerpts
Blindness
Research in visual attention has also revealed several ways that people don’t see what is in their visual field. This is simply how the human visual system works.
Inattentional blindness is the “looked-but-failed-to-see” effect. It occurs when attention is focused on one aspect of a scene and overlooks an object that is prominent in the visual field and is well above sensory threshold.
Change blindness is a failure to notice that something is different from what it was. Large changes to a visual scene are very likely to go unnoticed if they occur during saccades (eye movements) because visual analysis is suppressed during that time.