If there is one common denominator in ATR Icing accidents it is this.
Or Fokker 100. Or anything with highly loaded wings. Primary design concern of transport aeroplane wings is cruise efficiency. When it comes to stall, they are not supposed to display the benign characteristics of C-150 and ice accretion generally does not tend to improve them. ATRs have both shakers and pushers, clearly showing their natural stall is somewhat vicious, which doesn't imply we should be deeply worried about it and start another "ATRs are dangerous!" frenzy.
tail icing/rear stabiliser stall was to blame?
Absolutely not. Tailplane stall results in very rapid pitchdown, not roll. During NASA tail stall tests with Twotter, intention was never to achieve stall, just to get to brink of it and record the aeroplane behaviour. Plan worked every time but once. Nose went from horizontal to 80° AND in about two seconds, despite the two test pilots initiating recovery action as soon as the control was lost.
Tail plane icing would be particularly critical on the underside.
Errr... yes, but that's not the way it works in real life. To have tailplane stall, first you have to have severe ice accretion on leading tailplane edge (failed boot in heavy icing), then flaps have to be very powerful and tail has to be in their wake. Failing on any of that, you'll pick up ice, lose some performance, increase stalling speed somewhat but you won't make vertical dive when the flaps are lowered on final.
FO doesn't understand symptoms, does exact opposite of what is required, thinks it's a wing stall
Provided official reports confirm the leaked info, it was the correct thing to assume.
Investigators have said the Colgan Air aircraft seemed to be flying okay to the moment that the pilots lowered the wing flaps in preparation for final approach as the airplane dropped below 2,000 feet.
They have got it correct. Surprise, surprise
In short order, the autopilot disengaged
Because stall warning fired.
the airplane's nose pitched downward
Losing speed in approach config with engines on idle, it tried to regain the trimmed one. Perfectly natural.
Because the panicked pilot pulled so hard that he overrode the stick-pusher!
before a final pitch downward.
As the aeroplane stalled. Q400 is very simple: you stall it, you die.
Regarding
The real reason behind regional turboprop icing crashes, it is very refreshing to read misinformed drivel about the aeroplane which is not Euro-made FBW airliner. Sad, but refreshing nevertheless.