Happened to me but not as drastic.
A few years ago I was removing a gearbox and engine from a 200 tdi Discovery i was scrapping for parts. Just enough room to get under to cut the rear prop with the gas axe, handbrake was on etc. as soon as I had cut though the prop, the car started rolling forward (only on a slight slope), managed to dart out and had a brick nearby to chock a wheel to stop it moving.
Was not alone so could have shouted for help if needed, but it made me more wary for the future.
I always double check now when jacking up or working on ramps, the safest way is a two or four post lift, but they are not always available.

Steve. 1968 Series IIA Pastel Green, nearly there project

Poor Dale was in a right state after the accident and is only just driving now but still in lots of pain when the loopy drugs start to wear off but is soldiering on as best he can and avoiding the morphine as well  FFRR MY06 facelift With TDV8 Alloys Zeros/ATR's
Mantec Sump Guard, Rigid Load liner, MY10 BT upgrade.

Zirconblue wrote:

I'm not sure what happens on the L322 with it in park and one end lifted off the road, i think the front end still locks with the gearbox?

The same would happen. The gearbox pawl locks the output shaft (functionally the same for the various boxes), but the centre diff allows inverse movement through the shafts.  Visiting from DISCO3.CO.UK
Discovery 3 TDV6 Auto HSE Zambezi Silver

Same also happens if you lift one wheel off the ground and don't have a brake on as the prop shafts can spin freely then with the diffs not locked... FFRR MY06 facelift With TDV8 Alloys Zeros/ATR's
Mantec Sump Guard, Rigid Load liner, MY10 BT upgrade.

I had my suspicions, but i couldn't get my brain to compute how the diffs affected it at 10pm after an early shift.

Wow! Shocking! the number of times I have been under my RR, previous RR, disco's Freelander's, etc.

All the best to Dale for his recovery.

One thing interests me does the D3 & D4 not have a hand brake that acts on the rear wheels like the FF. Should this no have stopped it from moving? or was it not engaged as part of the repairs? 56 TDV8 Vogue SE
9 Freelanders, 2x 2002 TD4ES, 2001 TD4, 2002 1.8GS, 2000 XEDI, 2x 2000 1.8ES, 2004 1.8 & 2000 1.8 GS (rolled)
91 Lotus Carlton (sold)
90 Lotus Elan (BRG)

If it was an automatic it's possible he didn't bother to apply it, lots of people don't bother with automatics. I don't see it as an effort to put it n and off though.

Ouch -that will hurt.
Very lucky.
Farming has it's share of challenges.
My closest shave involved a 12 tonne twin axle tipping trailer hitched to a big John Deere Tractor.
The tractor uses a hydraulic lifting towing hook that lifts the ring on the trailer drawbar up to a point where the tip of the hook sits directly under the plate. You lock it there and then the tractor and trailer drawbar are as one... Pivoting around the hook and ring. Having had trailer attached all day we were mid harvest. This was about my tenth load.
With trailer fully laden with malting barley, I reversed the trailer into the storage shed to tip the grain.
Being in a hurry (to get back to combine about 3 miles away) I got out of the tractor, opened the grain chute and positioned the trailer, getting back into the tractor - starting to tip the load - the grain starts to come out - but a minute or so later - at three-quarter tip, the grain stops flowing with the trailer still with about 8 tonnes of grain in it.
Leaving the trailer "up", I exit the tractor cab to go and investigate. Due to the position of the grain store wall and the newly tipped grain, and how the tractor was positioned I could not access the chute lever that had dropped back and closed the chute (I had obviously not fully opened to pass the clip that retains it). The only way to it was over the drawbar of tractor and now raised trailer body - and then release the lever from the other side. I crossed the drawbar by standing on it and went and released the grain chute once more - grain starts flowing, and I head back the way I came...
As I stepped on the drawbar again I felt the trailer move, as the balance of the trailer shifted.
At that moment with one foot on the drawbar and one mid-air, the drawbar detached from the tractor and the weight of nearly 8 tonnes of grain and a tipped trailer body at one end of a chassis was balanced by a 17 stone farmer...
The drawbar flew upwards at speed as the trailer followed Newtons law, and as I was thrown a little sideways, the solid steel 8" square box section drawbar brushed my cheek as it went up, and the hydraulic hose (with a sealing pin if detached) whipped hard against my ribs as it was wrenched from the tractor connector.
I fell sideways just behind the tractor, dislocating my shoulder. No more than 5 seconds later, I looked up to see the drawbar and chassis starting to head back down. Incapacitated and stunned from what had happened I couldn't move much, and frankly had no time to. The drawbar landed back with a hefty thump no more than 18" from my chest showering me in bits of broken concrete from the floor. The main lifting cylinder then over pressurised by the sudden weight of trailer body coming to a sudden stop vented hot hydraulic oil in a jet all over me through the safety valve. The trailer body then thumped back on the trailer chassis.
I got up, and fell over almost immediately onto my dislocated shoulder because I had slipped in the oil.
At that point, the other tractor and trailer working - with my cousin Bill driving pulled in to unload.
An ambulance was called.
It later transpired that the lever that should have locked the drawbar tight in the towing hook had got loose. Not a problem when the weight was downwards on the drawbar - but when the load was tipped, the ring given enough time could exert enough pressure to unhitch itself.
In all the other runs the trailer had emptied before this had time to happen. Only the falling grain chute lever and my going to sort that out with trailer still up - gave it enough time and the change of balance to detach.
I got away with a hot oil shower, three smashed ribs and a dislocated shoulder. It could have easily been very much worse.
Strangely I always double check our trailer hitches now - every time I get out of the cab...

So I know how that chap feels. Each day since then has been a bonus.
It happened in August 1993 - so as you can see, it's still fresh in my mind. I can still taste the oil... Range Rover Vogue SE SDV8 - L405 (now sadly sold)
BMW i3 (fantastic little runabout)
Kioti NX6010 Tractor
Yamaha Big Bear ATV
And a whole heap of other kit...