We all know it takes a chain of causes to make this sort of tragedy happen.
It is not surprising that the manufacturer gives itself a clean bill of health (again). Keen pprune watchers will recall the rudder pcu saga and remember United 585 or US Air 424 and indeed Silk Air? More recently, KQ509 (a 737-800) makes for interesting reading, given that the entire wreckage was left to be pillaged in the swamp outside Doula.
I was interested here to check the issue with the Trim Tab.
"
In addition, a motivating factor for examination of the left side tab mechanism is the fact
that the inboard attach bearing was found with all of the bearing balls missing. It was
subsequently found (see Enclosure 2 Metallurgical Exam) that this condition existed at the
time of the accident."
That's all fine then, because the pilots got it wrong, so let's forget about the AD on this issue and any manufacturer related issues...