Relax, Henra, it's nothing personal.
What I wanted to point out was the involvement of the disconnection of the AP immediatly followed by violent roll.
Correct. Violent roll comes from stalling (or aileron hinge moment reversal at Roselawn). ATR picking up a ****load of ice feels very mushy - recommendation to fly manually in heavy icing is quite sensible.
This could be to some extent due to the unpowered ailerons in connection with icing on the horns.
Heaters do their work just fine. I don't recall any incident or accident because of failed flight controls horns heaters. In my 6 years on ATR, I lost them only once, which prompted mightily rapid descent to MSA, below freezing level.