Watch your airspeed
No question about that, end of story, but ........... wasn't this guy fresh off the Airbus, and if he "thought" that the A/T was engaged he wouldn't be concerned that the thrust levers were stationary, being what he was used to?
Never flown an Airbus, so sorry if I'm off beam, but isn't it true that the Airbus throttles don't "hunt" all the time, but remain fixed ?
Just a thought, 'mindset' can be a real enemy.