Rover Traction Issues

Coming back from the West towards Big Red recently we were swapping places with a TDV6 Range Rover Sport.

As we got to Big Red he was ahead and went up the easier track (but not the chicken track).
To our surprise he bogged down just below the crest.

No big deal everyone stuffs up occasionally.

With the car blocking the track we went straight for steeper track, ran straight up it, spun around on the top positioning ourselves on the crest about 10m from and above the Rover.

I love to see real in the field examples of cars performance and so set we up to watch and record.
Suspecting an issue we also made a quick cup of coffee.

Down it backed and came at it again getting more or less to the same spot.

I had a short talk to them and they seemed aware of the issues and fiddled a bit with
the traction control , dropped of a passenger and went back to give it a third go when I took these photos.

He got no further, I noticed he had good tyres 255 18's and he said they were down.

No doubt dropping tyre pressures would have got him further, but then next time the track may have been steeper.
The key point being that the cars performance was clearly sub-standard and its a powerful torquey expensive machine.
And the owner seemed to know what he was doing.

So why did this happen?
To me there was no obvious issue - I thought these things were well sorted by now and you just turned the knob and it did it all.
(Maybe I have seen to many 4wd ads).

It was midday, the sand was soft but not overly so, I was running ST-Maxx tyres which are tough but not exactly sand tyres like his AT's.

Looking at the photo's can we deduce anything ?

First it was a sensational day to be out their.

In the first photo things are looking good, the tracks relatively smooth.

In the second photo, taken just as it was about to stop you can see that the
crest in front of the rear wheel is building up, the front wheels less loaded and tellingly, the sand being thrown back from the front wheel is in bursts - indicative of intermittent loss of traction.
Could be poor suspension control on little moguls or perhaps traction systems braking the wheel.
As the sand looks relatively smooth I suspect traction control.

I do note that in another current thread "Now thats a Surprise" reference to Simpson road test in which the Rovers suspension couldn't handle it.
In this case there was ample time for shock cooling.

After 4 failed attempts we left.

I don't know much about these cars and welcome any comments.