20 hours later they are cited that they cannot board without China's approval. Legally uncharted grounds whether they could or could not. Looks they take the cautious side for the time being.
Superior methodology (transcending numerous cultural / psychological / cognitive norms and obligations) is how I would go about it.
For example: banning the conflation of opinion and fact, like what's going on (and always goes on) in this thread, a behavior that is protected (doing otherwise "is not what this site is for").
If an imperfection is noted: log it, investigate, improve. Rinse, repeat.
Also: best prepare one's will, life insurance, etc before undertaking such a project.