A nameless BA mate told me that until this incident he never checked the latches
I always checked the cowl latches in my time on the 'Bus'. At the time the walk round mandated that they were checked, either from the front (crouch down) or from the side by the wing tip whilst checking the nav lights.
Then 'someone' mandated that checking the cowl latches was a maintenance procedure and 'not required' by the flight crew.
AFAIK 'most' crews still check the latches.
Not proportioning 'blame' in any way, just stating how the responsibilities changed with the reduced turnaround times.