I'm thinking this almost certainly had to be in the dark if it was an off-route accident, but that would put it later in the evening this time of year. I have a hard time imagining a hiker with John's experience just wandering off a snowless trail in daylight and falling down a chute. Of course, possible AMS and exhaustion are two factors that can complicate the equation, but again I keep going back to his experience level. Thirty years hiking. Sixth trip up Whitney. The guy was no noob - he knew what he was doing on a mountain or a trail.
Unless the group got an egregiously late start from Outpost, or a similarly late departure from the summit, I have difficulty digesting a scenario that would have John in this area after nightfall. Assuming you're leaving the summit at, say, 1:00, and moving down at an absolute snail's pace of 1 mph, you'd still be here at around 7:00. It wouldn't begin to dusk until about 8:30, right? Full dark around 9:00? Add in the fact that nobody on the trail that day reported noticing him between TC and OC - and a hiker in trouble usually will draw some attention - and it still mystifies me. I haven't seen a time of day listed in any article for when his group saw him at the cables - that would be a nice fact to have while we're speculating. Which is, of course, what we're doing.
