This is a non event,
I agree there is some hysteria here but an incorrect readback that was itself missed leading to a TA is not a "non event". In Australia it is reportable so by definition...
14km at 1667 kmh takes about 30 seconds.
900 knots closing speed is 1667 kmh
no one was in imminent danger,
I disagree and so did the crew of at least one aircraft.