I'm not to well up on the towing arrangement on that truck but to me it looks like by attempting to pull the Disco out with the winch/tow rope quite high up has transfered the forces generated to the weakest point which in this case looks to be the mid point of the chassis, add to this the front being chained to the front vehicle has caused some damage.
I can see what they were attempting to do and I've done this many times myself, attaching 2 vehicles together and using their combined pulling power to rescue a bogged vehicle. Now this should only be attempted if you know what your doing and full control should be exercised over the drivers of all 3 vehicles, ie 1 man in control of the job, as long as everybody is driving in the lowest gear possible, in low range all axles/diff locks etc in, then it should be ok. This shouldn't be attempted when trying to winch a bogged vehicle out.
I would always prefer getting the winch out in most cases as it's safer, more controlled, less likely to cause any damage and easier to stop if something looks like it could go wrong.