Robin also confirmed that the Captain left the cockpit (possibly to use the toilet) and was prevented from re-entering the cockpit. Lubitz did not respond to repeated attempts by the Captain to gain entry to the cockpit or communications from ATC and ...other aircraft.
Robin also described the co-pilot's breathing as normal on the CVR in the final ten minutes of the aircraft's descent. Communication appeared normal between the pilots for the first half hour, though Lubitz's responses while running through the checklist for landing at Dusseldorf appeared to become terse and 'laconic' before the Captain left the cockpit.
Robin's comments today appear to rule out any suggestion of incapacitation of crew and was a deliberate act.