Taking into consideration what actually happened, are you really confident in your pronouncement that the crew had all the boxes ticked prior to commencing their 'circle to land' maneuver?
IMHO the question still remains why the screwed up the straight in approach. From various posts it is suggested that the 'circle' was commenced because they were too high for a straight in. If true, that is a huge error on vertical profile. How? If they were so far offset laterally after an autopilot flown approach, that is also a huge error. How? If both were true then one can only wonder WTF was going on. Personally I can't believe the latter where there was huge vertical & lateral error. The FDR + CVR will tell us.
Given the wind conditions I also can't believe that a turbo-prop crew would not plan for a straight in. The talk about FMS approaches: if the autopilot was following an FMC profile it should have been backed up with raw data monitoring; basic radial + DMA + altimeter. How they got themselves in such a pickle is the mystery.
I can't remember seeing the metar for their arrival. Usually someone posts it. I don't know how to do that from archives. Any chance, someone, please.
The facts should come to light quite quickly and all else is pure speculation.