I'm curious about the aircraft Take Off Weight. It seems to me that FL 380 is quite a high flight level for an initial climb.
Anybody knows the maximum altitude at ISA +20?
As of 18:00 today, the temperature was ISA -4. With a short flying time and 30 empty seats FL380 doesn't seem unreasonable. And anyway, an upset due weight/alt/temp would not have lost more than, perhaps 10 000'.