It was always going to be pilot error no matter what the background circumstances were.
Let this be a lesson to all commercial pilots in these days of increasing and aggressive, all-enveloping computer control of aircraft.
When in doubt use your skills as a pilot, take manual control and FLY the damned thing!
Sadly, all too often we see total reliance on the Flight Management Systems to the detriment of flying skills and with tragic results such as those at Phuket.