These guys didn't see each other, isn't that the point?
That was the immediate cause I suppose....but there are a lot of factors that play into the traffic conflict occurring that need to be considered as well.
I understand your point....what in heavens name does teaching steep turns and training syllabus standards have to do with this at all.
Rather than evoke an argument about that....lets focus on likely causes, the reason for those factors, and how the situation in that particular bit of airspace be improved so that we never have a repeat of this tragedy where some vey good people sadly lost their lives.
This is something that can happen to any of us.