Not watching the TCAS/not doing anything about it? Happens elsewhere too:
On 6 April 2012, a Boeing 737 and an Airbus A330 aircraft were on converging tracks at FL 360 (en route surveillance-based control). As the aircraft approached each other at the same level, the controller received a short term conflict alert (STCA) and noticed the aircraft were 5.2 NM (9.63 km) apart. The controller issued instructions to both aircraft to achieve vertical separation, which was established when the distance between the aircraft reduced to about 3.5 NM (6.48 km). See ATSB investigation AO-2012-048.
although in this case, "The controller immediately instructed the flight crew of the A330 to descend to FL350. The crew acknowledged and advised that they could see the traffic on their TCAS". Bit late for that...
Our airline is all airbus and hence if you left in the AP at high cruising levels then all you would get is a gentle 1g turn.
Not much of a turn!
