I'm in agreement with others that the wx conditions, while difficult, were not outside the capabilities of the aircraft. A two engine go-around should not pose a problem.
I'm more wondering about other possibilities. What if the AP wasn't engaged? CX had an incident in the -400 a while back where a go around was initiated but the AP wasn't engaged. Is it possible it this case that TOGA was pressed, but no firm pitch up was made? Given the temperatures, is it also possible (borne out of sim tactics) that there is an unofficial emphasis on "get the gear up quick in the go-around)?
Fatigue, both acute and chronic would play a part. Seems to be an issue at EK.
Automation reliance would play a part. A modern issue for mos airlines.
Negative training would play a part.
I've not flown the 777 so this is just my theory. Thoughts?