Thanks for answering my question, namely how does the collision resolution in TCAS work? (Different from, say, TCP, which uses randomness)

EDIT: FAA PDF on TCAS 7.1 - https://www.faa.gov/documentlibrary/media/advisory_circular/...

This story is a moving example of the self-improvement going on in global air traffic industry; perhaps sometimes slowly, but definitely self-improving. The following book compares the transparency of the air traffic industry with the lack of transparency that currently exists in the medical sector, where errors are denied:

https://www.amazon.com/Black-Box-Thinking-Psychology-Paperba...