Maybe the leg danglers in the back might have assumed that the pilots were competent to carry out a simple ground taxiing manoeuvre.
That is just the sort of complacency I mean - the old safety adage that ASSUME makes an ASS out of U and ME seems appropriate.
The left turn was clearly used for positioning, presumably to get into wind for the line up to the parking spot - which the right turn was meant to achieve.
The 'authorities' will doubtless use the video clip as part of their investigation and there is an outside chance that there may be extenuating circumstances in the cause of this accident but I won't be holding my breath.
How many flight safety courses and seminars have you been to where the root cause of an accident/incident is immediately obvious from the first look? I've done plenty although some turn out to be even more of a f**kup than first glance might show.
Not being part of the US Military, I won't get to see the accident report or investigation so I stand by my assumptions/observations until proved otherwise.