OK, you’re right. Stall warning, stick shaker ... and the pilot pulled back on the column. Yikes.
Then one wing apparently stalled and they rolled over hard.
Tragic.
Pilots are always taught from day one to immediately push the nose down (stick forward) in this situation, as well as other reactions like apply full power and level the wings. But nose down is first and foremost.
It's not likely the pilot reacted to a stall shaker warning by pulling the nose up.