My sense is that Beijing thought that they had no other option. Once this virus has run its course in Western societies, we will get a better sense of its actual impact, mortality, and probably also get a good idea of what Beijing had to cover up in Wuhan.

While failures in the West deserve a full accounting of any incompetence, the negligence of Beijing is the proximate cause and they don't want this back on them when this is all over. But having high-level MFA reps stand up and try and promulgate wild theories now is a heavy salting of the earth in US-China relations, and if they had wanted to be seen as a responsible state actor, apologies followed by aid would have been welcomed by all.

Another missed opportunity by Beijing in favor of domestic repression and international aggression.