Oh, give this "computer denying" schtick a rest!
If the pilots didn't configure the aircraft correctly, then they were responsible for crashing the plane. The A320 gives pilots more protection from their mistakes than many types but it's not designed to hold their hand all the way to the gate. Regardless of the opinions of some, the "RETARD" call is meant to be a reminder to perform an action (bring *both* levers to idle) if it has not already been performed - *not* an instruction from the computer to the pilot to do so.
Again, Rananim claimed that the A320's ability to give a pilot reverse on one side in the situation these pilots were in was an example of an Airbus design flaw, until he discovered that the 777 will allow the exact same thing.
I reckon it's this callout:
18:48:26.7 HOT-2 reverse number one only.
that (dependent on translation) is the key. It sounds like for whatever reason the pilot manipulating the throttles perceived that as "bring only one lever back".