You really need to re-read that NYT report, DE.
#1 The report is NOT an NTSB report, and despite the ineptitude of the NTSB, they are the 'authorities' on final determination.
#1 That said, even the NYT report puts the responsibility FULLY on the ATC. If you can't see that ... I'll spell it out for you.
The ATC SAW THERE WAS AN IMMINENT COLLISION and was therefor responsible for immediately TAKING ACTION.
Turn left - yeah, but we want to go visual and evaluate and avoid for ourselves.
Hyup - perfectly reasonable, eh ?
Nope:
TURN LEFT IMMEDIATELY - a whole horse of a different colour, my friend. No discussion allowed by a pilot (or two pilots) that want(s) to do it 'their way'.
QED - even from a very flawed NYT op ed. Not an investigation, sir.
My initial diagnosis is 100% STILL ON THE TABLE - IN SPADES NOW.