I think ATC has a big question to answer here. Why the hell would you vector a plane to land in the opposite direction of a departing aircraft on the same runway? At any rate, TCAS also has a big part to play in collision avoidance. It's not just up to the pilots scanning visually or manually looking at a radar screen. I wonder if the A350 got an RA or something and pulled up a bit too much in response.

EDIT Just read it was an uncontrolled airport as i posted this, so i guess ATC is out of the picture.