pax britanica
That was largely because the captain flying held the stick back against the pusher all the way down to the ground. It was an unfortunate accident where if they had just sat back and done absolutely nothing for a bit they would have been fine. The stick shaker activated early because the anti ice was turned on and the captain induced the pusher by heaving back on the stick. Pure piloting muppetry.
The Dash 8 300 also has a pusher but the smaller 200 and 100 don’t.