ok, I'll leave my quiet corner, even though I'm not a pro, but there are a few points I'd like to make:
#1: looking at how long it took this list to come up with a precise description of what the AB systems do with regards to breaking/spoilers/TR when the TL are in a non-idle position, the pilots flying this airplane had just a few seconds to analyze the situation and come up with the right answer. (that is, assuming that one of the TL was really not only not in the idle detent but so far forward that it prevented breaking action + 22.5°?)
#2: on moving or non-moving thrust levers: on the Boeing, the TLs are a means of bi-directional communication. If the pilot has on hand on the levers, he'll get direct tactile feedback of what the plane's current thrust setting is. That's an additional, very direct channel of communication besides the gauges or displays. AB has eliminated this direct feedback channel. So the pilot has to obtain thrust information through other sensory input. Given the fact that today's cockpits are rather quiet, probably only visual by reading and understanding the data on the displays. In a stressful situation like this one no doubt has been, this will take infinitely longer than registering the tactile feedback from a moving lever.
#3 assumptions of situations: many of the rules by which aircraft systems work do assume certain situations. TLs idle, main landing gear depressed, wheel rotation means we have landed and wheel breaks and spoilers can be activated/deployed. If one or more of the above inputs are not present, the situation becomes ambiguous. How can the system assess the situation when on TL is in full reverse and the other in CLB? How can the system understand what the PF's intentions are with this?
The way I understand the diagram provided further up, the logic is quite simple: all the factors are ANDed together and if one is not "TRUE", the whole situation is not "TRUE"... In this case: one TL out of the area that is considered "TRUE" for landing, you're clearly not landing.
This binary logic might be overly simple for humans who operate, and more importantly err in a continuum of analog values.
So what I'm saying is this:
even though the original error might have been a human factor (and no, I'm not stating this as a fact, just as a hypothesis), the chain of events unfolding seems to be one of miscommunication between the airplane's systems and the pilots operating it.
If it should indeed be concluded that this accident was due to human error, then I do hope that system/human communication and system complexity are listed in the "contributing factors" section.
pj