I've been giving this a bit more thought as to how he got in that position.
He could well have been sat dead centre when he tracked over the axles, if not why would he not reposition himself, no weight on the bucket at that time, he would be free to slew anyway he needed to get in line, so I have to assume he and everybody else was quite happy thats things were safe at that point.
As he started to pass the balance point at the rear of the trailer he had the bucket placed on the ground to steady him/herself. Wouldnt we all.
This is where it gets tricky and is what I was hinting at in this thread
https://www.heavyequipmentforums.com/Forum/showthread.php?t=15342
when I said
For all those that think they have the experience / bottle / nerve, to do it. Set an excavator up and climb over something, be it a log, rail track, girder, concrete kerb, whatever, but make sure your bucket does not slide or your tracks spin, now go and do it on some steel plate and achieve the same
IF he did not bring the dipper in as he tracked back the tracks would have spun and the machine would have slipped sideways as it pushed against the dipper that was holding it.
How many ops have you seen that slide the bucket when coming off benches or down steps. That is ok on muck out on site but not steel on steel.
I suspect this is what has happened up to the point where the video starts.
He is now sat on probably an inch or two of trailer and very few options left.
At the point the video starts I reckon he had only one option and that was to get assistance. Whether that be another machine, trailer, winch, block and tackle or just a strong coffee he needed help.