Friend of mine went for an assessment trip in the A320 simulator in Indonesia. Instructor had visual scene set to good visibility and no cloud and cleared for take off make left turn.
The captain under test glanced over his left shoulder just prior to initiating the turn. Immediately the Indonesian check pilot in the simulator demanded to know why the pilot looked outside before the turn. The pilot replied it was an instinctive check to make sure all clear since it was a visual departure.
The instructor got angry and said that pilots should never look outside in the A320 because the TCAS is always to be trusted.