This was being said to be Ison remnants, but (the ghost of) Ison's current position is at sunrise not sunset so I was dubious.
Now theorised as rocket launch remains.
I'd come across the photo and original ABC caption earlier but didn't get a chance to follow up at the time. Surely a case of mistaken identity -- comets' tails simply aren't straight and tidy like that.
There was indeed a satellite launch which might fit. [See:
Atlas V launches NROL-39 from Vandenberg]
A couple of photographers had been commenting on ABC's corresponding Facebook post with their observations, and they both stated it was only visible for a short time before dissipating. Later, another shared
this comparable image he'd taken after a SpaceX launch (Falcon 9). Seems like a much better fit.