Some pilots turn the auto pilot on soon after takeoff. If this aircraft had just taken off, odds are low the autopilot was on, although it is possible. However if the autopilot is malfunctioning, the pilots can turn it off.
I don't know if you guys remember, but years ago 737s had some issues with rudder hardovers resulting in at least 2 crashes (Denver, Pittsburg). That was not an autopilot issue, but a hydraulic issue. There could be a mechanical malfunction, but as far as I remember none of them have involved driving the aircraft into a nose high stall.