I noticed on the video submitted yesterday that the pilot showing a normal A320 landing after going to idle immediately pulled both reversers to full and his hand and fingers were above the throttles or at least to the top with the reverser controls.
If the TAM crew used the older method of only pulling one reverser into reverse if one was inop I can see only having the little finger to prevent advancement of the other throttle if the throttle physically advances. If they used the older method of one reverse to prevent that small increase in #2 engine they may have inadvertently, to prevent #2 from going into reverse, not gotten it all the way back to idle. His comments that #2 was stuck and he couldn't move it back must play a big part in this accident.
I have never flown an airplane where you could go from idle to full reverse position without waiting for logic to confirm reversers were positioned properly, then increase reverse power symetrically. From what I have read here the A320 reverser levers will go to full reverse position even if they are inop.