It was interesting to listen to the various passengers interviewed for the main national evening news bulletins of both CBC and CTV News here in Canada.
They all had the same story. A relatively uneventful landing, given the weather conditions, with the passengers even applauding the landing, but then the plane keeps on cruising down the runway. All interviewed then described a serious of bumps ("a roller coaster ride" said one) and flames roaring past the windows prior to the aircraft coming to rest.
The flames prior to the plane stopping its progress was common across all the descriptions (all from passengers from the rear of the plane), suggesting that the landing gear and or the engines had collapsed or detached sufficiently early for the flames to have arisen and be observed.
One other phenomenon, noticable particularly in the CBC's footage of police getting out of their vehicles on the taxiway adjacent to the tail of the AF plane, was the fact that the ground around the police cars seemed to be tinged with white, even though they were not actually near the flaming plane and the foam produced by the fire engines.
Was it possible that there was a very localised hailstorm just as the plane landed, causing the plane to skid down the runway on ice from the hail?