I've read that an observer watching an object fall toward a black hole will never see it cross the event horizon. For example, see the following Stack Exchange question.
I also know that a black hole merger is characterized by 3 phases: inspiral, merger, and ringdown as discussed at the following link.
That site describes the ringdown as follows:
Immediately following the merger, the now single black hole will “ring” – oscillating in shape between a distorted, elongated spheroid and a flattened spheroid. This ringing is damped in the next stage, called the ringdown, by the emission of gravitational waves. The distortions from the spherical shape rapidly reduce until the final stable sphere is present, with a possible slight distortion due to remaining spin.
To me, this seems to contradict the idea that we never see an object cross the event horizon.
If we never see them merge due to time dilation, then how can we detect gravitational waves of merging black holes?
I know that a black hole might not qualify as an "object", and that the merger of two event horizons might be a special case. If so, then please also explain how we could witness the merger of a black hole with a neutron star.
EDIT: Prompted by an answer to my question, I want to focus my question on how we can observe the RINGDOWN that occurs after the merger.