Most aviation accidents are not the sole result of pilot error or the sole result of mechanical failure. They are most often a result of the two. Often, a mechanical error will occur, and is then compounded by another type of error.
Imagine you are a driving a car down a busy road, and smoke starts coming from under your hood. You take your eyes off the road and are busy scanning the gauges to see if the smoke is from engine overheating or whatever, when you notice your fuel gauge is nearly empty. Now you have a situation that is making you concentrate on what to do when...BLAM! You rear-end a car that had stopped in front of you.
In avation parlance, this is known as "getting behind the curve". While you were troubleshooting the problem, you forgot to drive the car. Often, when a pilot encounters a problem, they become so engrossed that they forget to do things like...keep the plane level or lower the landing gear or flaps. Next thing they know, the stall indicator sounds, they are alarmed and overcompensate and then it is katie bar the door.
You explanation makes a lot of sense. I can relate to the car analogy.
Now that I think about it, fighter pilots really have to get to the point where everything they do is instictive and not waist time thinking about what to do.
Unless there was some unforseen structural failure in flight, it looks like a stall. There may have been other things that could have happened but that is why good pilots are always thinking (without thinking), "what if?" When your low and slow your mind should always have a forced landing plan.
I'm doing what I say I shouldn't do. I'm speculating. A control cable could have gotten stuck. A control surface could have jammed. A purse could have jammed the rudder pedals. Eyewitnesses and the NTSB will, hopefully, solve this one.
If the engine misbehaved in a previous flight that day, there is a serious question of the pilots competence. You don't go flying with passengers knowing the plane isn't 100% at take off. In addition since the pilot knew there was potential engine trouble he should have been prepared for it. Instead when it happens he stalls the plane and kills everyone on board. Sounds like repeated serious pilot error to me.
Our neighbor just had his car side-swiped by the teenager across the street. She was reaching down to grab her ringing cell phone. Getting behind the curve can apply to cars, planes and many other situations, as you so rightly pointed out. Excellent point! I could see it very easily happening.