...he draws the conclusion that whilst nothing can be ruled out, there is no evidence of significant or extraordinary activity in the ITCZ that night or any unusual updrafts.
Maybe not unusual from a met aspect, but is it
common to fly through the centre of such updrafts, which he also admits I believe, could have been topping out at 51,000 ft, having burst through the surrounding tropopause ...
which
could have happened that dark and stormy night?