Single spey,
I cannot really say how well this coordination went between ATCOs as seeing something written on paper it can be hard to fully feel how everything was dealt with.
No doubt the ATCOs concerned have gone over the scenario in their heads so many times and questioned their actions to the nth degree. An ATCO who believes they know everything and has nothing to learn is a dangerous one and not a type I have encountered here in the UK. WE can be arrogant buggers but that doesn't mean incapable of seeing faults in ourselves.
The Swiss Cheese model used in TRM and CRM training highlights how it is seldom one event that causes an incident but a variety of events and it is plugging that hole. AAIB who investigated this came up with reasonable and realistic proposal to try to ensure that events such as this are exceptionally rare and all concerned have accepted the findings.