From what little I've read, I understand a typical 737 stall speed to be in the region of 110kt with everything hanging out, more like 130-140kt clean.
No idea what winds aloft were like, but surface winds at the time were in the order of 6-8kt.
This crate lost 170kt in about half a minute, if the data's to be believed, ultimately reaching a
groundspeed of 115kt. That has to be getting close to the stall, if not actually beyond it. Could that sharp right turn be explained by a spin entry?
At 07:36 you see the rate of climb fall off while the speed decreases, although this is groundspeed not airspeed so harder to draw conclusions. That said: Are we seeing pilot/autopilot hauling back on the stick to arrest a sudden sink due to windshear? Did they then drive it straight into an even meaner cell that did them in?
My friend and I applied for airline jobs in Australia, but they didn't Qantas.