My concern is not so much icing during the approach or G/A itself, but accrued icing during the approach preparation in the hold and vectors towards the ILS.
Time over time again, I have seen crews putting faith on the " wiper/bolt" ice indication to estimate wing icing. This is completely wrong and extremely dangerous. Still, some people even teach this during line-training
To me, the upset occured at the moment that the Leading Edge Flaps/Slats became UP. This rings an alarm bell to me.